The Impact of Surgical Quality Control in Multi-Institutional Group Trials Involving Adjuvant Cancer Treatments

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Abstract
Quality control involving surgical treatment in multi-institutional cancer trials is important because the results of postoperative adjuvant therapy might be obscured by inadequate surgery or pathologic examination of the specimen. In 1975, the Southeastern Cancer Study Group (SEG) initiated a randomized clinical trial of adjuvant immunotherapy (Corynebacterium parvum [Propionibacterium acnes] vs. BCG) in melanoma patients with nodal metastases. During review of the results several years later, 20 of 136 patients (15%) entered into the study were judged as surgically ineligible. Of these 20 surgically ineligible patients, 13 have relapsed so far; many were taken off the study as immunotherapy failures, when, in fact, they were surgical failures. Compared to the 116 surgically eligible patients, the 20 ineligible patients had a shorter median survival (4 vs. 25 mo.) and a lower 1-yr disease-free survival rate (36% vs. 62%, P = 0.01). The 2 groups were balanced equally with respect to prognostic factors. Because of these findings, minimum surgical and pathologic guidelines were established for each adjuvant therapy protocol in the SEG. Surgical quality control was reviewed by a surgeon in each institution prior to randomization and again by a surgical investigator centrally. Pathologic criteria were also defined more precisely. The problems with surgically ineligible patients have since been virtually eliminated. Quality control measures for surgical patients entered into cooperative group trials is an essential part of the protocol design and data review. To evaluate properly the impact of adjuvant therapy, each clinical trial must comprise a uniform group of surgically treated patients.