Talk:Colorectal cancer

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Reviewed version: July 12, 2006
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Contents

[edit] Question about asprin & BCG

Does anyone know why combination therapy using asprin and BCG isn't more popular? It seems safer and less expensive.

Well, start conducting trials whether it also decreases mortality. JFW | T@lk 22:50, 7 August 2005 (UTC)

[edit] Alternative explanation for epidemiology

The prevention section states: Lifestyle: The comparison of colorectal cancer incidence in various countries strongly suggests that sedentarity, overeating (= high caloric intake), and perhaps a diet high in meat (red or processed) could increase the risk of colorectal cancer.

The same epidemiology strongly suggests that the use of sitting toilets increases the risk. The dietary fiber theory has been tested for decades and has been shown to be invalid. See this link [1]

The use of squat toilets is a much more probable explanation since it is consistent throughout the developing world and pertains directly to colon hygiene. Does anyone mind if I do a brief edit on this subject?

--Jonathan108 16:46, 7 October 2005 (UTC)

I've seen your postings before. There is more evidence for a role of fiber than for your toilet theories. Please don't do a brief edit this subject. JFW | T@lk 21:39, 9 October 2005 (UTC)
Hear, hear. You (Jonathan108) keep saying there is evidence for your toilet theories but I have yet to read any that qualifies as good evidence. Besides, while the dietary fiber theory might be taking some hits, that does not mean that it implies that your theory is better. Just because A does not imply B, that does not mean that not A implies B. Alex.tan 20:33, 21 October 2005 (UTC)
Of course it doesn't mean that my theory is better. It only means that something new is needed. My theory is quite plausible from many different angles, and was even advocated by Dr. Denis Burkitt, the originator of the fiber theory. It deserves to be considered, and not dismissed out of hand as you both seem to have done.--Jonathan108 16:36, 2 April 2006 (UTC)

Proving causation is really difficult, and your ideas qualify as WP:NOR. How do you propose testing for your hypothesis? I can think of several methodological hurdles you'll have to jump before your opinion can be proven scientifically. Wikipedia is not the forum for this sort of delibrations. Please try a blog. Cheers. JFW | T@lk 23:57, 2 April 2006 (UTC)

I would like to offer piece of epidemiologic evidence for thought. There is a large immigration of Japanese to Hawaii. The incidence of colorectal cancer in Japan is low and the incidence in Hawaii is moderately high. Studies of immigrant populations demonstrate that the incidence of colorectal cancer in the Japanese rises to Hawaiian levels following immigration. For sporadic colorectal cancer, this demonstrates the importance of an environmental contributions. I will provide the relevant reference in this location when I have it.Jcromwell 14:52, 19 November 2006 (UTC)

True, but the same migrant cancer risk story holds for female breast cancer. Ideally your conclusion from that observation should embrace both diseases (if in fact they are separate diseases), and dietary change offers one possibility. Toilet design, to my eye, does not. --Dan 20:37, 26 March 2007 (UTC)
There is another western habit that offers a very plausible explanation for the migrant breast cancer risk. See this link http://chetday.com/breastcancerandbras.htm --Jonathan108 01:21, 29 March 2007 (UTC)
So you're saying Japanese women don't wear bras whilest in Japan and start wearing them after moving to Hawaii, thereupon increasing their breast cancer risk? And furthermore this bra-wearing habit increases over three generations, thereby increasing the breast cancer risk from the baseline Japan risk up to standard US risk over a period of roughly 75 years? --Dan 18:46, 4 April 2007 (UTC)
Continuing the debunking of this notion, it is well-known that obesity is a strong risk factor for breast cancer. This would be something that increases in migrant groups and that is associated with tight bras as well. Here's an abstract of a recent paper:
Int J Cancer. 1999 Jul 2;82(1):23-7.
   Stage of breast cancer in relation to body mass index and bra cup size.

   Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. ixh1@cdc.gov

   Most studies on women with breast cancer indicate that obesity is positively associated with late-stage disease. Some results have shown a similar relationship between breast size and stage. A recent study found that the association between body mass index (BMI) and stage was limited to cancers that were self-detected, suggesting that the BMI-stage relation may be due to delayed symptom recognition. We examined the relationships between stage and both BMI and breast (bra cup) size, stratified by method of detection, using data from a population-based case-control study of 1,361 women (ages 20-44 years) diagnosed with breast cancer during 1990-1992. Height and weight measurements and information on bra cup size, method of cancer detection and other factors predictive of stage at diagnosis were collected during in-person interviews. A case-case comparison was conducted using logistic regression to estimate odds of regional or distant stage rather than local stage in relation to BMI and bra size. Odds of late-stage disease were increased with higher BMI [adjusted odds ratio (OR) for highest to lowest tertile = 1.46, 95% confidence interval (CI) 1.10-1.93] and larger bra cup size (OR for cup D vs. cup A = 1.61, 95% CI 1.04-2.48). These relationships were not modified by the method of detection. Differences in etiologic effects, rather than differences in detection methods, may explain the relations observed between stage and both BMI and breast size.

--Dan 18:53, 4 April 2007 (UTC)

Neither of the above comments debunks the notion. Obesity would increase the pressure of the bra on the lymphatic system. Obesity is also associated with increased time spent wearing a bra, since bralessness would be more embarassing for obese women. --Jonathan108 11:26, 5 April 2007 (UTC)

[edit] Smoking

The article states "Smokers are more likely to die of colorectal cancer than non-smokers", but doesn't give any source for the fact or indication of how much of an increased risk smoking presents. I googled the info and came up with a study conducted by the American Cancer Society that supports the claim. I'll edit accordingly. -- ktaylor

Thanks, well done. Perhaps we should start using Wikipedia:Footnote4 here. JFW | T@lk 13:35, 12 October 2005 (UTC)

[edit] Third or fourth most common cancer

An anonymous editor 209.7.119.196 feels that colon cancer is the fourth most common form of cancer and the second leading cause of death among cancers in the Western world. However, at least in the U.S., it is the third most common form of cancer according to the American Cancer Society colorectal cancer facts & figures . Andrew73 20:35, 15 December 2005 (UTC)

[edit] Fiber, yes but

In last week's JAMA[2] it was found that dietary fiber intake was inversely associated with risk of colorectal cancer in age-adjusted analyses. However, after accounting for other dietary risk factors, high dietary fiber intake was not associated with a reduced risk of colorectal cancer. JFW | T@lk 14:26, 25 December 2005 (UTC)

That's an interesting article, even though it's almost a meta-analysis. There seems to be an implcation that dietary fiber is acting as a proxy for folate intake. Here's a quote from the paper:

"In the age-adjusted model, dietary fiber intake was significantly associated with a 16% lower risk of colorectal cancer in the highest quintile compared with the lowest (pooled age-adjusted RR = 0.84; 95% CI, 0.77-0.92) (Table 2). This association was attenuated slightly but still remained statistically significant after adjusting for nondietary risk factors, multivitamin use, and total energy intake (multivariate model I). Additional adjustment for dietary folate intake further weakened the association (multivariate model II). In the final model, which further adjusted for red meat, total milk, and alcohol intake, only a nonsignificant weak inverse association was found (pooled RR = 0.94; 95% CI, 0.86-1.03; P for trend = .75; multivariate model III). " --Dan 20:44, 26 March 2007 (UTC)

[edit] Deleted alternative therapies

This may be controversial, but I deleted the alternative therapies section; therapies of unproven value such as mistletoe, etc. should not be given the same weight as therapies with proven benefit such as chemotherapy, etc. Thoughts? Andrew73 16:45, 26 December 2005 (UTC)

Since there were no references cited in that section of the article, it was probably best to remove it. It might be possible to have such a section if it described studies of the "alternatives". I'm not sure that any of the alternatives that were listed are really significant.

--JWSchmidt 17:39, 26 December 2005 (UTC)

Thanks for digging up the information. It seems that some of the information is for supportive therapies, i.e. to prevent nausea or vomiting, or preclinical testing. The clinical trials with curcumin may have potential, but overall, the information listed probably isn't notable enough to be in the article. Andrew73 17:45, 26 December 2005 (UTC)

I'm generally in favour of mentioning commonly used alternative remedies in a seperate section, but only if there is an indication that this is indeed commonly used, popular etc. Even those with a demonstrated benefit in trials may not necessarily be included if nobody uses them. JFW | T@lk 17:52, 26 December 2005 (UTC)

[edit] List of victims

Suddenly this page had a list of people with colorectal cancer. Many of them were of doubtful notability, and none have changed the public perception of colorectal cancer. I have removed the list and strongly discourage its recreation. Generally speaking, these lists are unnecessary, unencyclopedic, indiscriminate collections of information etc etc. Personally I would include only people of international fame whose illness has made a change in the public perception of the disease, such as Kylie Minogue and breast cancer or Michael J. Fox with Parkinson's disease. JFW | T@lk 18:11, 22 March 2006 (UTC)

[edit] Surveillance

This subject heading could be merged into prevention under the heading of secondary prevention. --Mansell 08:56, 9 June 2006 (UTC)

[edit] Liver mets

Gut this week: resection of liver mets. JFW | T@lk 19:32, 11 July 2006 (UTC)

[edit] Good Article nomination has failed

The Good article nomination for Colorectal cancer has failed, for the following reason(s):

More than half of this article consists of lists. These need to be re-written as prose. Also, very short sections should either be expanded or merged. Worldtraveller 14:45, 12 July 2006 (UTC)

[edit] Small error, but I'm a wiki newbie, not sure where to put this input-

In this article, FAP is said to have a 100% colon cancer association by age 40. I don’t think that is correct. Age 40 is significant in FAP because it is the mean age of cancer diagnosis, not the age by which they all have cancer. FAP has a near 100% progression to colon cancer, but the mean age is 39 (call it 40). I think that the sentence should read "FAP progresses to colon cancer in nearly 100% of all individuals, at a mean age of 39."

In fact, I am not aware of any specific age by which 100% have cancer, because I believe that 100% malignant progression is approached asymptotically with no specific associated age.

Here is the appropriate reference to clarify the issue- Bussey HJR. Familial polyposis coli. Baltimore: The Johns Hopkins University Press; 1975.

Here is a reference that discusses the median age of benign findings and some of the epidemiology of progression- Campbell WJ, Spence RAJ, Parks TG. Familial adenomatous polyposis. Br J Surg 1994;81:1722-33.

I hope that helps, I am new to this and not really sure whom to notify of an error. It isn't a big error, by any means.

Thanks.

[edit] Recent modifications

Hi I am a medical student in Hong Kong and I have modified the article to make it more comprehensive and (hopefully) easier to read.

  • symptoms: i have categorised it according to bowel symptoms, constitutional symptoms (due to catabolic effect of tumor) and also symptoms of systemic metastasis. Some new symptoms were added, e.g. tenesmus. Melena is not PR bleeding nor hematochezia (bloody stool). Anaemia is a diagnosis but not a symptom. Pallor and hepatomegaly are clinical presentations (signs) instead of symptoms.
  • Dukes classification: it is still commonly used among surgeons since it guides management and indicates prognosis
  • Surgery: I have further categorised it into curative, palliative, bypass, fecal diversion and open-and-close according to surgical principles. Please note the differences between surgical management in colon cancer and rectal cancer.
  • Radiation: also, I have summarised the paragraph, and please note the differences between colon and rectal cancer.

I think the format of the article can be improved, however I don't have time to do it at the same time. Maybe someone else would like to take up this job? sctonyling 16:43, 18 July 2006 (UTC)

added external links to nccn.org and also added other viable screening modalities currently implemented.--Vtak 03:49, 18 August 2006 (UTC)

[edit] Per rectal bleeding

Please kindly note that per rectal bleeding is not peri-rectal bleeding. Per rectal bleeding refers to bleeding through the rectum; "peri" is a prefix meaning surrounding, making the term "bleeding surrounding the rectum". sctonyling 05:08, 13 August 2006 (UTC)

Or it may read easier without "per." Andrew73 04:18, 14 August 2006 (UTC)
if we put it as rectal bleeding, it means "bleeding from the rectum", which is difficult from per rectal bleeding (bleeding through the rectum). To prompt easier reading, I have changed that into "bleeding through rectum (per rectal bleeding)". In the same essence, I have edited the passage so that medical terminologied precedes with layman explanation. I have as well categorised the symptoms for easier reading.sctonyling 04:41, 16 August 2006 (UTC)
I think bleeding through the rectum just confuses things. Doesn't make any sense -- Samir धर्म 04:46, 16 August 2006 (UTC)
"Rectal bleeding" is standard terminology. I haven't heard of anyone describing this as "bleeding through rectum," but this may reflect my American bias! Andrew73 12:42, 16 August 2006 (UTC)

[edit] reduction in calibre of feces

Newly added in section Symptoms.sctonyling 04:41, 16 August 2006 (UTC)

[edit] Africans vs. African Americans

Consider this statistic: Colon cancer is nearly 15 times as common in black Americans as in Africans.

The reference for this statistic is the Journal of the Royal Society of Medicine, cited here:

Temple NJ, Burkitt, DP, The war on cancer--failure of therapy and research: discussion paper, J R Soc Med. 1991 February; 84(2): 95–98. online at http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1293097

Now that the fiber theory has been disproved, how do we explain this statistic? --Jonathan108 18:21, 19 February 2007 (UTC)

Well, not your squat toilets, for sure. Can you please go away? JFW | T@lk 21:42, 19 February 2007 (UTC)
Oh, the fibre theory is not dead yet. And African-Americans get colorectal cancer from overcooked hamburgers and being overweight - both recognised risk factors well beyond your silly loos. JFW | T@lk 21:47, 19 February 2007 (UTC)

If you still believe the fiber theory, I suggest you read this article from the Boston Globe.

Strange that you would cling to Burkitt's fiber theory and regard his other theory with such contempt. It was published in prestigious peer-reviewed journals like the Journal of the Royal Society of Medicine. Are their standards lower than Wikipedia's? --Jonathan108 02:02, 20 February 2007 (UTC)

I may have read the paper too quickly, but I don't see any explicit references to squat toilets in the JRSM paper. Andrew73 18:14, 20 February 2007 (UTC)

No, that paper didn't refer to squatting, but the following articles discuss its benefits:

D P Burkitt, Some diseases characteristic of modern Western civilization.Br Med J. 1973 February 3; 1(5848): 274–278.

Denis P. Burkitt, Br Med J. 1972 June 3; 2(5813): 556–561. Varicose Veins, Deep Vein Thrombosis, and Haemorrhoids: Epidemiology and Suggested Aetiology

Burkitt, DP, Hiatus hernia: is it preventable?, Am. J. Clinical Nutrition, Mar 1981; 34: 428 - 431. (discusses squatting in great detail)

Also, Burkitt's book, "Don't Forget Fibre in Your Diet" acknowledges that squatting could be as important as diet in preventing many "western" diseases.

Burkitt is listed as the author in 108 articles in Pubmed, but 95% of them are not available online. I'm sure that a large percentage of them also talk about squatting. --Jonathan108 22:58, 20 February 2007 (UTC)


[edit] CEA

Comment about: "Prognosis

Survival is directly related to detection and the type of cancer involved. Survival rates for early stage detection is about 5 times that of late stage cancers. CEA level is also directly related to the prognosis of disease, since its level correlates with the bulk of tumor tissue."

Whether CEA is truly of clinical use is still controversial, as far as I know.

[edit] TNM Classification

The description of T1 talks about invasion through the Submucosa and into the Lamina Propria. The Lamina Propria is in fact luminal to the Submucosa (see other wikipedia article), and so this appears to be impossible. I would update it, but am not sure of the correct TNM levels for this cancer

86.8.137.70 10:59, 10 May 2007 (UTC)

[edit] Chromosome 8

Someone added a region on this chromosome as a risk factor. This is very novel and nowhere near the other syndromes. It has not even been printed, see this abstract. JFW | T@lk 19:15, 16 July 2007 (UTC)

According to Online 'Mendelian Inheritance in Man' (OMIM) 114500 there are numerous other regions that are relevant for colorectal cancer. Why link to one single study? JFW | T@lk 14:28, 17 July 2007 (UTC)

[edit] Fiber theory "controversial"?

All the evidence I've seen indicates that the fiber theory is now considered erroneous. See this link (again!). Unless someone can present recent evidence to the contrary, I'm going to correct this statement: "The nature of the relationship between dietary fiber and risk of colorectal cancer remains controversial." --Jonathan108 16:31, 20 July 2007 (UTC)

[edit] Aspirin

doi:10.1053/j.gastro.2007.09.035 indicates that anything less than 2 aspirin tablets (325 mg) a day for 6 years are needed to make meaningful changes to colorectal cancer risk. JFW | T@lk 07:32, 3 February 2008 (UTC)


[edit] Image is not helpful to layperson -- suggested minor aides to help

The image at http://en.wikipedia.org/wiki/Image:Colon_cancer.jpg was not helpful to me because I could not spot the described features. Maybe if I had a medical background, it would be more obvious. Suggestions: pointers indicating healthy tissue with other pointers indicating the abnormal features that were mentioned. By the way, I was Dx'd on 10/4/2007 and Wikipedia was one of my resources. Surgery was successful, it couldn't have gone better. Thanks Wikipedia and all the other resources -- they all helped in their own ways Funchords (talk) 06:35, 20 February 2008 (UTC)

The balance between clutter and clarity is always difficult for technical images. Instead of adding numerous circles and arrows to the image, I decided to explain it in the legend. I hope this helps. Emmanuelm (talk) 15:12, 20 February 2008 (UTC)

Funchords, I uploaded a new picture just for you. Is it better? Emmanuelm (talk) 12:40, 12 April 2008 (UTC)

[edit] Nonpolypoid (Flat and Depressed) Colorectal Neoplasms

Sohel‎ (talk · contribs) added mention of these in the intro. http://jama.ama-assn.org/cgi/content/abstract/299/9/1027 discusses other (pre)malignant lesions of the colon that seem to be harder to detect and are more likely to be malignant. This is still in need of confirmation, and should probably be mentioned in the article but not in the introduction. JFW | T@lk 09:35, 7 March 2008 (UTC)

[edit] Error in 'Follow-up' section

The statement "Routine PET or ultrasound scanning, chest X-rays, complete blood count or liver function tests are not recommended" appears to be incorrect. My read of the cited articles indicates that such routine follow-up tests *are* recommended.

I'm not an expert, so I will defer correction of this to someone who can confirm that it is indeed an error. —Preceding unsigned comment added by R Steven Adams (talk • contribs) 21:42, 10 April 2008 (UTC)

Steve, I just read the NCCN Practice Guidelines 2008 document (cited in article). Follow-up is detailed in the chapter "Post-treatment surveillance". It is a bit more complicated but, overall, there is no overt mistake in the article. I would, however, shorten this section for the sake of readability. Emmanuelm (talk) 12:55, 12 April 2008 (UTC)

[edit] Chemoprophylaxis

A useful review to replace the WP:SYNTH we have now: doi:10.1053/j.gastro.2008.02.012. JFW | T@lk 15:19, 27 May 2008 (UTC)