Dissecting Chemotherapy Part 5: Contribution of Chemotherapy to Survival of Colon Cancer Patients

L M Carethers wrote the following in the International Journal of Gastroenterology & Hepatology,  Gut 2006;55:759-761 doi:10.1136/gut.2005.085274:

  • The current gold standard for treating patients with advanced colon cancer is chemotherapy with 5-fluorouracil (5-FU) based regimens. This standard is based on compelling clinical trials utilising 5-FU and levamisole, and demonstrating a survival benefit for patients with stage III (Dukes C) colon cancer.
  • Although there is no set standard for treating stage II patients, some stage II patients do receive 5-FU chemotherapy.
  • Stage I patients with colorectal cancer do not receive 5-FU as their prognosis is excellent with removal of the tumour.
  • Stage IV patients may receive 5-FU for palliation (note: this is not cure).

Dissecting the Gold Standard of Colon Cancer Treatment

In 1975, Dr. Charles Moetel, a renowned oncologist of the famed Mayo Clinic in Minnesota, USA, found that the lives of Duke’s C colon cancer patients could be prolonged when treated with a combination of 5-FU and levamisole (a drug used in sheep, swine and cattle to control stomach and intestinal worms and nematode parasite infections). 

In this study, 971 patients with Duke’s C colon cancer who had undergone surgery were divided into three groups and given one of the three treatments. The actual median follow-up time is 6.5 years.

Treatment

Number of patients

Number with recurrence

Number died

Surgery only

315

177   (56.19%)

168  (53.33%)

Levamisole

310

  172   (55.48%)

158   (50.96%)

Levamisole +  5-FU

304

   119   (39.14%)

121   (39.80%)

Benefit of Levamisole + 5-FU over  surgery only (no chemotherapy)

Less recurrence by 17.05%

Less death by 13.53%

Source:  Moertel, C. G. et al. Fluorouracil plus levamisole as effective adjuvant therapy after resection of stage III colon carcinoma. Annals of Internal Medicine. March 1995. Vol: 122: 321-326. http://www.annals.org/content/122/5/321.full.pdf

The authors concluded that Fluorouracil plus levamisole is tolerable adjuvant therapy to surgery; it has been confirmed to substantially increase cure rates for patients with high risk (stage III) colon cancer. It should be considered standard treatment for all such patients.

The therapy with 5-FU + levamisole: caused nausea, infrequent vomiting, stomatitis, diarrhea, dermatitis, fatigue and mild alopecia. Approximately half of the patients had leucopenia (lowering of the white blood cells).

The unanticipated toxic reaction to 5-FU + levamisole: 40% of the patients had abnormal liver function test results during the course of the therapy. Their toxicity were reflected in elevated alkaline phosphatase levels (which peaked approximately 7 months after onset of therapy), elevated aminotransferase (AST) levels, and elevated serum bilirubin besides causing fatty liver.

Questions:

  1. Does the result show that if you don’t undergo chemotherapy after surgery, you will die?
  2. Does it not show that without chemotherapy 53.3% of patients were dead but even if you have undergone chemotherapy almost 40% died anyway?
  3. Does it not show too that even with chemotherapy 39% of the patients still suffered recurrence?
  4. Would it not be prudent to weigh this advantage against quality of life issues, taking into account the acknowledged side effects of chemotherapy?

From the above data it is clear that chemotherapy reduced recurrence by 17 % and reduced death by 13.5 % but not without side effects which are often brushed off as insignificant.

Chemotherapy is proven to be beneficial by only a slim margin (13% to 17%). Indeed, from the academic point of view, the result is statistically significant. This would please the statisticians and the scientists, but I am not sure if it pleases cancer patients at all. I believe this is not what patients (especially those in the poor developing country) are looking for. They are seeking for a REAL cure (not a MEDISAL CURE either!). If this is not possible, at least they expect a much greater chance of achieving it. I wonder if anything less than 20% benefit is good enough?

Chemotherapy causes severe side effects in most patients. It is not like an “ant-bite” as one oncologist would tell some patients. With less than 20% benefit, is it worth the gamble?

One question comes to mind: Can this slim margin of benefit of chemotherapy not be achieved by some other non-invasive or non-toxic means? For example, does it ever occur to people that by just a change of diet or taking of herbs, perhaps we can also increase our chances of healing colorectal cancer and the result could be better than chemotherapy? At CA Care we have presented many case studies showing that indeed this hypothesis is valid and has merit — herbs and change of diet and lifestyle can prolong meaningful survival better than chemotherapy!

Gold Standard Plus Targeted Therapy

Today, oncologists have a good number of chemo-drug mixes for patients with advanced stage colon cancer. A new generation of “smart bomb” or targeted-therapy drugs can also be added to the mix to help control (ah, not cure?) the cancer. Examples of these regimens are:

  • FOLFOX (leucovorin [folinic acid], 5-FU, and oxaliplatin)
  • FOLFIRI (leucovorin, 5-FU, and irinotecan)
  • CapeOX (capecitabine and oxaliplatin)
  • Any of the above combinations plus either (not both) Avastin (bevacizumab) or Erbitux (cetuximab)
  • 5-FU and leucovorin, with or without Avastin
  • Capecitabine, with or without Avastin
  • FOLFOXIRI (leucovorin, 5-FU, oxaliplatin, and irinotecan)
  • Irinotecan, with or without Avastin
  • Erbitux alone
  • Vectibix (panitumumab) alone

Avastin and Ertibux are now being commonly offered to cancer patients in Malaysia. Vetibix is still unknown here … but soon it will hit our shore. But what do they say about Avastin and Ertibux? Two things are clear: They are expensive. And they don’t cure colon cancer !

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