Lab Soft News

Teen Trumps Pathologist; Diagnoses Her Own Crohn's Disease

Crohn's disease, also known as granulomatous colitis and regional enteritis, is an inflammatory bowel disease (IBD) that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms. It primarily causes abdominal pain, diarrhea, vomiting, or weight loss (see: Crohn's disease). As any pathologist knows, the characteristic granulomas of the disease that distinguish it from ulcerative colitis may be difficult to spot, so a recent article (see: Teen diagnoses her own disease in science class) does make some sense. Below is an excerpt from the piece with boldface emphasis mine:

For eight years, Jessica Terry suffered from stomach pain so horrible, it brought her to her knees. The pain, along with diarrhea, vomiting and fever, made her so sick, she lost weight and often had to miss school....In her Advanced Placement high school science class, she was looking under the microscope at slides of her own intestinal tissue -- slides her pathologist had said were completely normal -- and spotted an area of inflamed tissue called a granuloma, a clear indication that she had Crohn's disease....[Her teacher], who has taught the Biomedical Problems class ...for 17 years, immediately went on the Internet to see whether Terry had indeed spotted a granuloma."I said, 'Jeez, it certainly looks like one to me,' " [he] remembered. "I snapped a picture of it on the microscope and e-mailed it to the pathologist. Within 24 hours, he sent back an e-mail saying yes, this is a granuloma." ...."This story carries a valuable lesson about how errors are found. It's very often by 'fresh eyes,' just like in Jessica's case," [a local pathologist] said. "Some specialty centers, recognizing the reality of perceptual error and the power of a second independent reading, are now requiring second reviews on certain types of smears and pathology specimens."

There are a few ideas that can carried away from this story. One of them is not that the average citizen can expect to second guess or reverse the diagnosis of a pathologist. Here are some of my first impressions:

• This is clearly a story about a highly motivated high school student with support from a talented science class teacher. Note above that her teacher "immediately went on the Internet" and searched for images of granulomas in Crohn's. A Google image search for "Crohn and granuloma" provided a large set of images showing the classic granulomatous lesion. It's an easy search once you get the hang of it but an option not readily available to a high school teacher a scant five years ago.
• Also interesting to note is that Jessica Terry or her parents had the presence of mind to request the slides from her biopsy from the hospital and she also thought to bring the slides to class to look at under the microscope. 
• The story is also a powerful reminder of the value of seeking a second opinion for significant or ambiguous diagnoses. Many healthcare consumers don't know this, but most pathologists will be willing to request a second independent opinion for cases. The patient should not be shy in putting such a request to either the pathologist or through the treating clinician.
• Finally, I was impressed by the apparent lack of defensiveness on the part of the pathologists who were quoted in the story. Perhaps they had no other choice, but I could envision them reacting in a less positive way under the circumstances.

Add Colonic Cancer to the List of "Lifestyle" Neoplasms

I was taught in my sophomore pathology course a long time ago that red meat eaters had a higher incidence of colonic cancer. The high incidence of the lesion in both Scotland and Argentina at that time were cited as evidence for the theory. I had never thought of dietary habits, including the ingestion of red meat, in the context of "lifestyle" choices like smoking and drinking. However, I now believe that this is the case.

I have posted a number of previous blog notes about the connection between lifestyle and health issues. See, for example, the following: Diabetic Tatoos: Lifestyle Merges with Medical Necessity, Seeking the Correct Definition for a "Lifestyle Disease". Now comes the news about new evidence of a linkage between alcohol and smoking consumption and colorectal cancer (see: Alcohol and smoking are key causes for bowel cancer). Below is an excerpt from the article with boldface emphasis mine:

A new global study has found that lifestyle risk factors such as alcohol consumption and cigarette smoking are important risk factors for bowel cancer. Researchers have shown that people who consume the largest quantities of alcohol (equivalent to > 7 drinks per week) have 60% greater risk of developing the cancer, compared with non-drinkers. Smoking, obesity and diabetes were also associated with a 20% greater risk of developing bowel cancer - the same risk linked with consuming high intakes of red and processed meat. Approximately one million new cases of bowel (colorectal) cancer are diagnosed worldwide each year, and more than half a million people die from this type of cancer. In Australia alone, it is the most commonly occurring cancer with more than 12,000 new cases diagnosed each year. According to [the] lead researcher [of the study], the most startling finding of this study was, "The strong, and largely, unknown association between high intakes of alcoholic beverages with risk of colorectal cancer."...On a positive note, researchers also demonstrated that physical activity lowered an individual's risk of the disease but surprisingly, there was little evidence to indicate that high intakes of fruit and vegetables were protective against bowel cancer.

Browsing the web, I discovered that Australians eat an average 38.1 kg (84.0 pounds) of beef per person per year (see: Major Commodities - Beef). This number has remained constant for the last 15 years. Beef consumption in the U.S. beef consumption, by way of comparison, averages about 66.1 pounds per person per year (see: Study reveals U.S. beef consumption statistics by age, income, gender, race, etc.). Chicken, as a dietary protein, is catching up fast.

It's fascinating to learn that colorectal cancer, as noted in the article quoted above, is the most commonly occurring cancer in Australia with more than 12,000 new cases diagnosed each year. For additional reading on the topic of colonic cancer in Australia, see: Meat Consumption and the Risk of Colorectal Cancer. In the U.S. and looking at estimated cancer cases for 2009, colorectal cancer is in fourth place behind lung cancer, breast cancer, and prostate cancer, using National Cancer Institute data. These rankings put aside non-melanoma skin cancers (see: Common Cancer Types). I also did not know that exercise lowered the risk of colonic cancer. I wonder if exercise somehow changes the bowel transit time, and therefore colonic bacterial flora, by increasing the titers of endogenous hormones? It has been shown in at least one study that mild concurrent exercise accelerates the orocecal transit rate (see: Orocecal transit during mild exercise in women).

So what do we take away from this discussion in terms of our own "lifestyle" issues? Not much that we didn't already know. Your best bet in order to pursue a healthy lifestyle is to exercise a lot, drink alcoholic beverages in moderation, forget about smoking, and eat your veggies. Use meat, particularly red meat and processed meat, as a garnish/condiment on your plate or not at all. If you don't like veggies, you may not be preparing them properly. Visit a good Indian restaurant to figure out what you are doing wrong.

Making Progress Toward Digital Pathology One Funeral at a Time

I have posted previous notes about digital pathology (see: Digital Pathology vs. Digital Radiology: A Broad Divide, "Eminence-Based" Surgical Pathology and the Digital Pathology Department). I have come to the conclusion that a near-total conversion to digital pathology is absolutely critical for progress in the field. As only one facet of this discussion, digital pathology is an absolute requirement for the evolution of integrated diagnostics, the merger of pathology, lab medicine, and radiology. I have posted a number of previous notes about this topic. Efficient image search, which will revolutionize the practice of surgical pathology, is also in its early development stage and will arrive main-stream in a few years.

A major barrier to the conversion to digital pathology, in contrast to digital radiology, is that there are few major economic drivers to encourage pathologists to adopt this new technology. Pathology reports, by and large, look the same to clinicians under this new technology, with the possible exception that images can easily be integrated into reports. In radiology by way of contrast, all new imaging modalities are digital. All of these new modalities have been actively supported and ordered by clinicians and have attractive profit margins.

Pathologists will probably not be getting calls from their hospital executives urging them to pursue digital pathology, particularly in these difficult economic times. Hence we have a large cohort of hospital-based pathologists who have few incentives to approach hospital leadership for the capital to convert to digital pathology. This also relieves them of the burden of mastering the new skill of image interpretation on a screen. The political hierarchy in pathology departments will also altered under digital pathology with more influence exerted by younger members of the department who have been trained in the new techniques.

I am reminded of a discussion I had some years ago with some young pathologists about generating surgical pathology reports using voice recognition and then requiring them to make minor edits to the report copy on-line. I asked them if this minor editing chore was a source of concern for them, all of whom had good keyboard skills. They said to me: "How else would you do it?" A very reasonable question from individuals who had not spent decades handing audio tapes to surgical pathology transcriptionists who then produced the reports. This leads me to the prediction that we will make progress toward digital pathology "one funeral at a time."

NYT Highlights the "Virtopsy" Used for All Military Autopsies

The virtopsy is an emerging subject of interest in medical diagnostics (see: Introducing the Virtopsy, a Variant of the Catopsy Theme, The Classic Forensic Autopsy on the Verge of Being Obsolete, Reinventing the Autopsy: CT Imaging as a Routine Part of the Procedure, Additional Discussion About Reinventing the Autopsy). I have referred to the procedure in some of my notes as the catopsy because of the combination of the classic autopsy and the CT scan. The New York Times has now given increased exposure to this new approach to the medico-legal autopsy with a front page story (see: Autopsies of War Dead Reveal Ways to Save Others). Below is an excerpt from it with boldface emphasis mine.

Under Capt. Craig T. Mallak, pathologists from the Armed Forces Medical Examiner System conduct autopsies and CT scans on all service members killed in Iran and Afghanistan. Since 2004, every service man and woman killed in Iraq or Afghanistan has been given a CT scan, and since 2001, when the fighting began in Afghanistan, all have had autopsies, performed by pathologists in the Armed Forces Medical Examiner System. In previous wars, autopsies on people killed in combat were uncommon, and scans were never done. The combined procedures have yielded a wealth of details about injuries from bullets, blasts, shrapnel and burns — information that has revealed deficiencies in body armor and vehicle shielding and led to improvements in helmets and medical equipment used on the battlefield. The military world initially doubted the usefulness of scanning corpses but now eagerly seeks data from the scans, medical examiners say, noting that on a single day in April, they received six requests for information from the Defense Department and its contractors....The medical examiners have scanned about 3,000 corpses, more than any other institution in the world, creating a minutely detailed and permanent three-dimensional record of combat injuries. Although the scans are sometimes called “virtual autopsies,” they do not replace old-fashioned autopsies. Rather, they add information and can help guide autopsies and speed them by showing pathologists where to look for bullets or shrapnel, and by revealing fractures and tissue damage so clearly that the need for lengthy dissection is sometimes eliminated.

As noted in the story above, there was initial reluctance on the part of the military officials to adopt the virtopsy but it has now proved its value beyond doubt. Also, and as  noted above, a wealth of imaging information is now being made available by the military that could potentially facilitate the rapid adoption of the virtopsy. It urgently needs to be adopted for civilian forensic cases as well as for standard hospital autopsies of patients who have died of medical diseases. However, I suspect that the virtopsy will only be slowly embraced by civilian forensic pathologists or hospital-based pathology departments. Here are the reasons behind my prediction:

• Civilian forensic pathologists are overworked and underfunded. Given the current financial downturn, the various city and state governments that support the services of the medical examiners are struggling to meet basic needs. They will probably have little interest in new initiatives no matter what their value. Many forensic pathologists may also balk at having to acquire the new skills involved in the interpretation of CT images.
• There is no question is my mind that virtopsies would yield far better results than current methods -- the success of the Army with the technology bears out this conclusion. However, there is no urgent driver in the civilian world analogous to that in the military of savings soldiers' lives on the basis of the new virtopsy findings about the nature of injuries.
• For hospitals and pathology departments, there is no reimbursement for autopsies and frequently inadequate compensation for forensic cases. On this basis alone, it may be difficult to convince chairpersons of pathology departments to sink capital into enhancements of the pathology suite and new training initiatives.
• The only bright spot in this story is the increased interest in the merger of pathology and radiology, discussed in many previous notes. If this trend takes hold, the notion of training pathology residents rotating through the autopsy service in the interpretation of CT images could be very appealing. For academic departments, there is also the intriguing possibility of extracting more usable information from autopsy cases.

An "Independent" Autopsy after the Death of a Relative in a Hospital

Any patient who dies in a hospital is entitled, at no charge, to an autopsy to determine the cause of death. If family members refuse permission for the autopsy, the physicians caring for the patient are then required by law to determine the cause of death. I recently came upon an article in the New York Times written by a woman whose previously well sister passed away in a hospital of septicemia (see: The Autopsy, a Search for Reassurance). In this article, she raises the issue of the need for an "independent" (i.e., private) autopsy. This article requires additional discussion. Below is an excerpt from it with boldface emphasis mine:

If I could have arranged for an independent autopsy by a pathologist outside the hospital where my sister died, I might have done it. But at the time, I had no idea how to go about it and felt too dispirited to try. Recently, I typed “autopsy expert” into a search engine and found Dr. William Manion, a pathologist and lawyer in New Jersey....Some clients hire him because they want to sue doctors, he said in an interview, but others are just looking for peace of mind. Some are upset because they feel doctors didn’t take the time to explain what happened....Similarly, he said that people whose relatives died of undiagnosed, advanced cancer sometimes recalled symptoms from a few months back that they might have overlooked or dismissed. He tells them that the cancer must have been there for a long time, and that they couldn’t have done anything....As for my concern that a hospital might try to cover its mistakes in an autopsy report, Dr. Manion didn’t buy it. Pathologists based in hospitals are reliable, he said, in part because they have to pass muster with various accrediting groups....The Web site for the College of American Pathologists keeps a list of board-certified pathologists who perform private autopsies. Most charge $3,000 to $5,000....But it’s important to decide quickly; Dr. Manion says an autopsy is best performed within 24 hours of the death, before organs deteriorate too much.

By New York Times standards, this particular article leaves much to be desired. Its fundamental flaw, in my opinion, is that the author turns to an individual, Dr. Manion, who derives financial gain from referrals away from hospital pathologists for a general assessment of them. He, in turn, describes hospital-based pathologists as "reliable," in essence damning them with faint praise. I have personally spent more than four decades in pathology and been involved with thousands of autopsies. I have never seen a single instance where an autopsy report was less than totally objective in terms of the cause of death, particularly in cases of potential malpractice. I have also been personally involved in numerous lively discussions with clinicians, including many surgeons, about autopsy findings. In the final analysis, the objective judgment of the pathologist about the cause of death of a patient has always held sway. The veracity of an autopsy report goes to the very core of the practice of the specialty.

I will also defend the right of any family to choose to have an autopsy performed by an "independent" and qualified pathologist without a relationship to the hospital where the patient died. In most such cases, the patient and family have had an uneasy relationship with hospital medical staff or administrative personnel. They may feel that they want to "do the best thing" for their relative or may be in a litigious frame of mind, with or without good cause. I agree with Dr. Manion that in the majority of such cases, the treating physicians have been uncommunicative or perceived by the family as uncaring -- this is frequently the basis for their mistrust of all of the hospital physicians. However, I would advise families seeking an independent pathologist to take some care that the individual selected is well trained and board-certified.

Corrected Definition for a Pod Lab and a Look at In-Office Labs

In a previous note (see: Pathologist Satisfaction with "Pod Lab" Positions), I used the term pod lab in an incorrect way. My better understanding of the term comes after a conversation with Joe Plandowski who consults in this area. His web site is Twincrest. A pod lab is synonymous with a condo lab and both terms are used to refer to an off-site histology lab used to process tissue specimens for a medical practice.  Medicare billing for both types of labs are highly restricted under CMS anti-markup rules and thus unappealing. The term that I should have used in my note was an in-office lab which is the proper term for a lab that is built, owned, and operated by a group of clinicians such as gastroenterologists or urologists. Such a lab processes tissue specimens obtained for diagnostic purposes by the physicians working in the group that are then read and reported out to the group by an in-house pathologist.

Joe tells me also that CMS (Centers for Medicare and Medicaid Services) is now in the process of loosening its regulations such that an in-office histology lab no longer needs to be built inside of the suite of offices of the medical group but will need to be located inside the same building. Joe also tells me that, in his experience, the pathologists engaged to interpret the slides that are processed by in-office labs most commonly work on a fee-for-service, contracted basis for the medical group.

The installation of an in-office histology lab and the interpretation of the slides by a pathologist contractor to the group can be extremely lucrative for the group. The development of such a strategy is a substitute for sending the specimens to a commercial surgical pathology lab or to the local hospital pathologists. The commercial labs will be hit hardest by this emerging business model because office practices are the major source of specimens for such labs. Hospital pathology groups will still maintain control over inpatient specimens and those outpatient specimens generated by physicians working within the health system. The quickening pace of the emergence of large clinical groups and the financial appeal of in-office histology labs for them suggests that pathology groups and commercial labs may soon need to write off much of their small-specimen, office-generated business.

Pathologist Satisfaction with "Pod Lab" Positions

In a recent post (see: Dayhawk Radiology and the Decline of the General Radiologist), I made the following statement at the end of the note:

A variation on this [pod lab] theme is for the urology group to submit their tissue specimens to a commercial surgical pathology lab for processing and then use their own in-house pathologist to interpret the prepared glass slides that are returned by the commercial lab. In fact, I have been told that many of the surgical pathologists who are practicing in this type of environment are very satisfied with their positions.

In response to it, Daniel Schneider submitted the following comment:

Your last paragraph attempts to put some positive spin on a sketchy practice designed to increase urologists' revenue at the expense of pathologists' and drives overutilization (in the form of excessive numbers of biopsies) at the expense of the patient, and the American healthcare system. Who are these pathologists who are "very satisfied" with that arrangement?

On one hand, Daniel is correct that my statement about the condition of pathologists working in pod labs is too general and somewhat ambiguous. I don't present the names of the individual pathologists who  are "very satisfied with their positions." On the other hand, this practice can be controversial so that I am not sure that I could, or would, publish such names even if I had then. To do such might expose them to harassment from their pathologist colleagues. He is also correct that the employment of a pathologist by a urology group could provide an incentive for the urologists to take more biopsies. After all, many of us still live in a fee-for-service world. Such an issue needs careful study but raises a different question than whether a pathologist should break ranks and serve as a member of a urology group.

However, let's run this thought experiment. Let's say that you are a pathologist who has spent a number of years in training including a fellowship in urologic pathology. Let's further assume that this individual cannot obtain a position working in his or her specialty area in a large hospital or academic center or receives a better offer for employment in a urology group. Would such an individual perhaps not prefer to work exclusively in urologic pathology, perhaps with a less grueling schedule, and give up some of the advantages of employment by a pathology group? For such an individual, the personal advantages might outweigh the more "politically acceptable" choice of working only with pathologists.

My goal here is not to put a "positive spin" on an emerging business model but rather to engage in a dialogue. Having said this, I will offer this blog forum to any pathologist working, say, inside a urology group, to discuss his or her degree of satisfaction. I am not seeking heated polemics but rather a balanced discussion including consideration of whether our teaching programs are not to blame in some ways for this problem. We may be turning out too many surgical pathologists whose comfort zone lies primarily in a specialty area of practice.

Carcinoma of the Pancreas in the News; Some Additional Information

I recently came across an article discussing the current mortality figures and other facts about pancreatic cancer (see: Pancreatic cancer one of deadliest forms). This type of neoplasm has been in the news lately with both Steve Jobs of Apple and U.S. Supreme Court Justice Ruth Bader Ginsburg suffering from it. Below is an excerpt from the article:

• Pancreatic cancer is one of the deadliest forms of cancer, with 37,680 U.S. cases each year and 34,290 deaths.
• The American Cancer Society says the five-year survival rate for pancreatic cancer patients is about 5 percent. Most patients die within six months because the cancer shows few symptoms until it is too advanced to be helped by treatment.
• Adenocarcinoma is more common and deadly. A rare but more benign type called an islet-cell, or neuroendocrine, tumor, is more easily treated.
• If the tumor looks like it can be removed, a complex surgical procedure called the Whipple procedure can help patients live longer, with overall five-year survival about 20 percent.
• Patients whose cancer is caught before it spreads into their lymph nodes may have up to a 40 percent survival.
  

It occurred to me that these mortality figures are not much different that those I learned when I was a medical  student and pathology resident almost 50 years ago. That's shocking in light of the fact that we today refer to some forms of leukemia and lymphoma as chronic diseases whereas they previously had a much more serious prognosis. As noted above, pancreatic cancer commonly becomes symptomatic late in the clinical course. Justice Bader's small lesion is said to have been discovered during a CT scan apparently performed for other reasons.

As noted above, the islet-cell, or neuroendocrine, tumor of the pancreas has a somewhat better prognosis than the standard adenocarcinoma of the organ (see: Islet Cell Tumors (Endocrine Pancreas)). Here are a few more details about this latter lesion with boldface emphasis mine:

Cancer of the endocrine pancreas includes a highly treatable and often curable collection of tumors. They are uncommon cancers with 200 to 1,000 new cases per year and occur in only 1.5% of detailed autopsy series. Islet tumors may either be functional (produce one or more hormones) or nonfunctional. The majority of functioning tumors that produce insulin are benign; however, 90% of nonfunctioning tumors are malignant. Many islet cell cancers are nonfunctional and produce symptoms from tumor bulk or metastatic dissemination. Because of the presence of several cell types in the pancreatic islet cells (alpha, beta, delta, A, B, C, D, E), the term islet cell tumors refers to at least five distinct cancers, which when functional, produce unique metabolic and clinical characteristics....Functional tumors may be too small in size to be detected by conventional imaging techniques.

The Classic Forensic Autopsy on the Verge of Being Obsolete

I posted a note on March 18, 2008, plus two follow-up notes, about what I then referred to as the catopsy, which I defined as a classic autopsy extended by the use of medical imaging techniques (see: Reinventing the Autopsy: CT Imaging as a Routine Part of the Procedure, Additional Discussion About Reinventing the Autopsy). At that time, I was unaware that the term virtopsy had already been used to refer to post-mortem imaging that was being performed in various centers. I subsequently published a note about the virtual-autopsy (i.e., virtopsy) (see: Introducing the Virtopsy, a Variant of the Catopsy Theme). My understanding at that time was that the virtopsy consisted of only the imaging component of an autopsy without histopathologic examination of tissue and was, therefore, an extension of the classic autopsy (see: Virtual Autopsy Offers Noninvasive Postmortem Exam).

At the 13th annual APIII conference held in Pittsburgh on October 19-23, I had the privilege of listening to lectures by three individuals who have been pivotal in the emergence of the virtopsy. They were Drs. Stephan Bolliger and Steffen Ross from the Institute for Forensic Medicine, Bern, Switzerland, and Colonel Angela Levy, Uniformed Services University of the Health Sciences, Bethesda, Maryland. These lectures (The Virtopsy Project: Novel Approaches in Post-Mortem Imaging, Drs. Bolliger and Ross; and The Virtual Autopsy and Postmortem Multi-Detector CT Imaging, Col. Levy) can be downloaded from the APIII 2008 web site (Wednesday, 22 October, 10:30 a.m. breakout session). Dr. Bolliger is a pathologist and Drs. Ross and Levy are radiologists. Caution: these two lectures are large PowerPoint files that download slowly but are worth the time and effort.

Having now observed the work being done by Drs. Bolliger, Ross, and Levy, I have personally come to the following conclusions about the virtopsy and the future of forensic pathology:

• The virtopsy now seems to be defined as a combination of classic autopsy techniques plus various imaging modalities. Dr. Ross is even performing post-mortem vascular imaging procedures using injected contrast material. However, the term virtopsy may be somewhat misleading because it refers to both a "real" autopsy and a "virtual" autopsy.
• Dr. Levy is focusing on the description and understanding of post-mortem artifacts as viewed by medical imaging techniques. Such knowledge, of course, is critical in the evolution of the virtopsy and extends the understanding of such artifacts that has been obtained over the years by pathologists.
• Because of the profound amount of new information that is now being added to the classic autopsy gross dissection techniques and microscopic observation of tissue, I personally believe that the forensic autopsy, as routinely performed in the U.S., is on the verge of being obsolete. I believe that most pathologists will come to the same conclusions after reviewing the two lectures referenced above.
• I urge all forensic pathologists to rapidly adopt the medical imaging techniques advocated and now demonstrated as practical by Drs. Bolliger, Ross, and Levy as soon as possible. This will enable a refinement of both standard and forensic autopsies techniques such that much more information can be obtained from the procedures and the information obtained can be better documented.
• Achieving broad adoption of the forensic virtopsy will be very challenging based on the following requirements of the virtopsy: (1) ready access to sophisticated medical imaging devices for most or even many of the procedures; and (2) ready availability of a forensic radiologist such as Dr. Ross to interpret the post-mortem images. Ultimately, I believe that the solution to this problem will be the cross-training of forensic pathologists in both pathology and radiology in order for them to interpret both gross/microscopic pathologic changes as well as the images produced by the various imaging modalities.
• I believe that early adoption of the forensic virtopsy in the better-funded medical examiner offices in urban centers will cause a medico-legal conundrum in other communities. The adoption process will begin to change the standard of practice for the forensic autopsy as interpreted by the courts. In those regions where the practice is not adopted, the defense bar may be able to challenge the validity of classic forensic autopsy findings as inadequate.

Seeking the Correct Definition for a "Lifestyle Disease"

I must admit at the start of this note that I thought I understood the definition of lifestyle diseases -- in my mind, the term referred to diseases caused by some action, or lack of action, on the part of an individual that caused a disease to develop. Examples of the former, an action taken, would be lung cancer caused by smoking or hepatic cirrhosis caused by excessive ethanol intake. It turns out that I was wrong in my use of the term. The causes of lifestyle diseases are based on the general behavior of populations rather than individuals. Here is the definition from the Wikipedia:

Lifestyle diseases (also called diseases of longevity or diseases of civilization) are diseases that appear to increase in frequency as countries become more industrialized and people live longer. They include Alzheimer's disease, atherosclerosis, asthma, cancer, chronic liver disease or cirrhosis, Chronic Obstructive Pulmonary Disease, Type 2 diabetes, heart disease, nephritis or chronic renal failure, osteoporosis, acne, stroke, depression and obesity.

The reason I was thinking about this topic was that a recent article had caught my attention (see: Molecular imaging that will bring about a revolution in diagnosis and drug discovery). Its categorization of cancer, dementia, and diabetes as lifestyle diseases makes perfect sense now that I understand the correct definition for lifestyle disease (boldface emphasis mine):

Molecular imaging is essential for a better understanding of life, because phenomena in living beings result from interactions between molecules. Masaaki Suzuki, of the Molecular Probe and Drug Design Laboratory, says, “Molecular imaging is the ultimate goal of life science.” Molecular imaging is expected to help in the detection of lifestyle-related diseases, such as cancer, dementia, and diabetes, at an early stage, as well as in developing good new drugs with the fewest side-effects far more quickly. 

Taking the example of cancer as a lifestyle disease, I do understand the idea that a longer life free of, say, infectious diseases, may increase the risk of developing cancer for an individual. Hence the notion that lifestyle diseases being synonymous with diseases of longevity. I also understand that living in an industrialized nation could increase one's exposure to pollutants or food additives that might be carcinogenic. However, I also suspect that some individuals are genetically predisposed to developing malignant neoplasms, partly as a result of having a less efficient or effective DNA repair mechanism, allowing more rogue cells to develop and proliferate. Here's an interesting little article on cancer immunology that includes a reference to the cancer immunosurveillance theory.