Active specific immunotherapy for stage II and stage III human colon cancer: a randomised trial 

Authors Vermorken J, Claessen A, van Tinteren H, Gall H, Ezinga R, Meijer S, Scheper R, et al 
Source Lancet. 353:345-50. January 30, 1999. 
Institutions University Hospital, Amsterdam, Netherlands; University Hospital, Antwerp, Belgium; Comprehensive Cancer Centre Amsterdam; INTRACEL corporation, USA. 
Support not indicated. 


Active specific immunotherapy with vaccines prepared from the patient's own tumor has shown some success in patients with melanoma and renal cell cancer. Two trials of tumor vaccines in colon cancer failed to reveal a significant benefit, but subgroup analyses suggested some benefit, particularly among patients who had a substantial immune response. 

This trial was designed to further study active immunotherapy in patients with stage II or III colon cancer, using an enhanced vaccination schedule (with four instead of three doses of vaccine) and with the vaccine prepared by a central laboratory to assure quality control.



Patients were eligible if they had undergone curative resection of stage II or III adenocarcinoma of the colon. 

Patients were excluded if there was intestinal perforation or peritoneal seeding, if patients had inflammatory bowel  disease, if the cancer was rectal, if the CEA level did not normalize within 21 days, if there was a prior history of cancer or if they were being treated with steroids or cytotoxic agents. 

Vaccine preparation

Surgery was performed at one of 12 hospitals. Tumor samples were processed at one central site. The tumor was minced, dissociated with collagenase and DNase and frozen. About 60% of vaccines prepared in this fashion contained normal GI flora, but none were declared unsafe for use.  Prior to administration, the vaccine was thawed and irradiated with 200 Gy. Each vaccine contained approximately 107 cells. The first two vaccinations administered to each patient also contained 107 BCG microorganisms. 

Randomization and vaccine administration

The specifics of randomization are not described in the article. Patients were randomized to either receive or not receive the vaccine, and were stratified by institution, tumor location and pathological stage. 

Patients who were randomized to receive the vaccine were given a series of four intradermal injections, starting 4-5 weeks after surgery.  The first two vaccinations were given one week apart, were injected in the anterior thighs and included BCG organisms. Vaccines three and four were administered at 3 weeks and 6 months (booster), were injected into the upper arms and did not include the BCG. 

Follow-up and analysis

Patients were followed up every three months for the first two years, every 6 months for the next three years and annually thereafter. CEA was measured at each follow-up, chest x-rays were performed regularly and CT scan and colonoscopy were performed annually. 

The primary endpoints were recurrence-free interval and recurrence-free survival (time to first occurrence of any malignant disease and time to occurrence of malignancy or death from any cause).  Subgroup analysis by pathological stage was also prespecified. Secondary endpoints included deaths from recurrence of colon cancer and all-cause mortality. 



There were 480 samples with adequate tumor cells. 161 patients declined to participate and 65 were ineligible, leaving 254 patients randomized (128 to vaccine, 126 to no vaccine). 

Patient and disease characteristics were well matched, and included (for both groups combined, unless otherwise indicated): 

  • Median age: 65-66 years; male: 68%
  • Right colon 40%; left colon 54%
  • Greater than 4 positive lymph nodes: 25 in control group, 20 in vaccine group
  • Stage II disease: 62%; stage III disease 32%
Vaccine and vaccine reactions

The mean time from tumor resection to the start of vaccine preparation was 2.98 hours.  Based on average specimen size and number of cells per gram of specimen, the authors estimated that their approach would yield enough tumor cells to prepare four vaccine doses in 88% of patients overall. 

Local reactions to the vaccines were more intense with the first two vaccinations, which contained BCG.  These included induration in all patients and some degree of ulceration in 93%.  Eight patients did not receive BCG in the second vaccination because of local reaction to the first.  Mild systemic reactions occurred in 22% of patients, severe reactions in 5%. 

Local reactions to the third and fourth vaccinations, which did not contain BCG, were less intense but did occur in most patients.  Induration greater than 10 mm occurred in 87% of patients with the third vaccination and 92% with the fourth.  Ulceration only occurred in 7% and 4% of patients with these vaccinations. Mild and severe systemic reactions were only present in 7% and 0.5% of patients. 


Median follow-up time was 5 years 4 months. 

Among all patients, recurrence of (any) malignant disease occurred in 31.7% of unvaccinated patients and in 19.5% of vaccinated patients. This was statistically significant.  This effect was not seen in stage III patients (41.4% vs. 34.9%). Thus, the reduced overall recurrence rate was due to a particularly significant effect among stage II patients (27.1% vs. 11.8%). 

There was a trend towards reduction in the combined endpoint of  malignancy or death, which reached significance for stage II patients (36.5% vs. 23.5%).  Overall mortality was not affected, but there were trends in reduction of disease-related mortality, particularly for stage II patients (16.5% vs. 8.2%). 


Author's discussion

The authors conclude from their study that active specific immunotherapy significantly lowers the recurrence rate of stage II and III colon cancer, mainly through an impact on stage II disease.  They speculate that the reason for the preferential effect on stage II disease is the lesser tumour burden. 

The authors argue that there are two reasons why this study showed a benefit, whereas two other trials did not. The first is the addition of a fourth vaccination at 6 months, and the second is greater quality control in the preparation of the vaccine by the centralized laboratory.  Adequacy of vaccine preparation facilities is thus an important issue. 

The authors note that adjuvant chemotherapy, which is effective for stage III patients, has not been shown to benefit stage II patients. Thus, immunotherapy would be a logical choice for stage II patients. Whether or not it would benefit stage III patients in addition to chemotherapy is an issue that they intend to assess in future trials. 



This study, which examined the effect of four doses of a colon cancer vaccine prepared from the patient's own tumor specimen, found a significant reduction in disease recurrence among vaccinated patients. Although mortality was not reduced, there was a trend towards reduction of disease related mortality, particularly in stage II patients. 

This was not a blinded study. Also, the details of randomization were not provided and it is unclear at what point in the process consent was obtained and at what point randomization actually took place.  It is also unclear how the study dealt with the withholding of adjuvant chemotherapy from stage III patients who received no vaccine. 

The results are promising, but one obstacle to the immediate applicability of this approach will be the necessity of vaccine preparation by a highly specialized and presumably centralized laboratory.  This represents a significant effort and cost, particularly for stage II disease which has a relatively favorable prognosis to begin with.  Furthermore, no significant effect on overall mortality has yet been demonstrated, although consistent trends were there. 

Further studies to improve the vaccine efficacy even further, to standardize and facilitate its production and to evaluate it in conjunction with adjuvant chemotherapy will be needed. 

February 21, 1998 


References related to this article from the NLM's PubMed database. 

Reader Comments

The following comments are from the corresponding author of the paper:

Date: Wed, 3 Mar 1999 
From: "Eertwegh, A.J.M..van.den" <> 

Thank you for your letter and for discussing our paper in the journalclub. Below are my comments on your summary of our paper. 

1) the first three vaccinations were weekly and the fourth vaccination was six months after operation. (The third was not after three months!). 

2) patients were asked for informed consent after the tumor was dissociated and provided that there were enough viable cells for four vaccinations. 

3) randomization was performed after the patient fulfilled all the inclusion criteria and after informed consent. 

If you have more questions, don't hesitate and E-mail me. 

With kind regards, 

On behalf of Prof. G.M. Pinedo 

A.J.M. van den Eertwegh, M.D. Ph. D. 

    I originally wrote that vaccine number three was given at three months. This error has been rectified. I appreciate this correction and the clarification of randomization and consent.  -- mj

March, 1999
From: samim celebi (chalabi) []

In regard of using vaccination in colon cancer patients, we are basically trying to increase tumor cell destruction by patient's own immune system (bcg helping), assuming this is confirmed.  Stage iii patients do not have a favorable response most probably because the immune system is like a tired horse, it cannot run anymore.

So in  that line of thinking we have to look at tests to determine the improvement in immunity in survivors and in those who improved and if that is the case, first we can identify people who can benefit and next we can look at specific as well as non-specific therapies to intervene in the immune system.

samim celebi (chalabi) md

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