Postoperative adjuvant irradiation with or without chemotherapy for rectal carcinoma

Impact of T and N stage and treatment on survival and relapse in adjuvant rectal cancer: a pooled analysis

PURPOSE

To determine survival and relapse rates by T and N stage and treatment method in five randomized phase III North American rectal adjuvant studies.

PATIENTS AND METHODS

Data were pooled from 3,791 eligible patients enrolled onto North Central Cancer Treatment Group (NCCTG) 79-47-51, NCCTG 86-47-51, US Gastrointestinal Intergroup 0114, National Surgical Adjuvant Breast and Bowel Project (NSABP) R01, and NSABP R02. Surgery alone (S) was the treatment arm in 179 patients. The remaining patients received adjuvant treatment as follows: irradiation (RT) alone (n = 281), RT + fluorouracil (FU) +/- semustine bolus chemotherapy (CT; n = 779), RT + protracted venous infusion CT (n = 325), RT + FU +/- leucovorin or levamisole bolus CT (n = 1,695), or CT alone (n = 532). Five-year follow-up was available in 94% of surviving patients, and 8-year follow-up, in 62%.

RESULTS

Overall (OS) and disease-free survival were dependent on TN stage, NT stage, and treatment method. Even among N2 patients, T substage influenced 5-year OS (T1-2, 67%; T3, 44%; T4, 37%; P <.001). Three risk groups of patients were defined: (1) intermediate (T1-2/N1, T3/N0), (2) moderately high (T1-2/N2, T3/N1, T4/N0), and (3) high (T3/N2, T4/N1, T4/N2). For intermediate-risk patients, those receiving S plus CT had 5-year OS rates of 85% (T1-2/N1) and 84% (T3/N0), which was similar to results with S plus RT plus CT (T1-2/N1, 78% to 83%; T3/N0, 74% to 80%). For moderately high-risk lesions, 5-year OS ranged from 43% to 70% with S plus CT, and 44% to 80% with S plus RT plus CT. For high-risk lesions, 5-year OS ranged from 25% to 45% with S plus CT, and 29% to 57% with S plus RT plus CT.

CONCLUSION

Different treatment strategies may be indicated for intermediate-risk versus moderately high- or high-risk patients based on differential survival rates and rates of relapse. Use of trimodality treatment for all patients with intermediate-risk lesions may be excessive, since S plus CT resulted in 5-year OS of approximately 85%; however, 5-year disease-free survival rates with S plus CT were 78% (T1-2/N1) and 69%(T3/N0), indicating room for improvement.

Rectal cancer: preoperative versus postoperative irradiation as a component of adjuvant treatment

The search for improved disease control and survival for resectable but high-risk rectal cancers has led to studies that combine all 3 modalities. For surgically resected, high-risk rectal cancers, postoperative chemoradiation has been shown to improve both disease control (local and distant) and survival (disease free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health Colorectal Cancer Consensus Conference. Three randomized studies showed improved overall survival (OS) and local control for patients treated with postoperative irradiation and chemotherapy when compared with surgery alone or surgery plus irradiation control arms. These include 2 US trials, Gastrointestinal Tumor Study Group and Mayo/North Central Cancer Treatment Group (NCCTG) and a Norway trial. Although most preoperative external beam radiation trials show reductions in local relapse with the addition of preoperative EBRT to resection, only the large Swedish trial of approximately 1,100 patients showed a survival improvement when compared with a surgery alone control arm for resectable primary rectal cancers. In a recent pooled analysis of 3 postoperative adjuvant rectal cancer trials (NCCTG 794751, NCCTG 864751, and GI Intergroup 0114) survival and disease relapse were dependent on both TN and NT stage of disease (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more positive nodes), T substage influenced 5-year OS (T1-2, 69%; T3, 48%; and T4, 38%; P <.001). Ongoing randomized trials are being conducted for patients with high-risk, resectable primary rectal cancers. The intent is to help define optimal combinations of postoperative chemoradiation (US GI Intergroup), to test sequencing issues of preoperative versus postoperative chemoradiation (Germany trial), and to determine if concurrent and maintenance 5-FU and leucovorin add to the benefits found with preoperative irradiation (European Organization for Research and Treatment of Cancer). For subsequent trials, it may be preferable to perform separate studies, or a planned statistical analysis, for different risk groups of patients (low, intermediate, moderately high, and high), as defined in the rectal cancer pooled analysis.

Impact of T and N substage on survival and disease relapse in adjuvant rectal cancer: a pooled analysis

PURPOSE

To determine the rates of survival and disease control by TNM and MAC stage in three randomized North American rectal adjuvant studies.

MATERIALS AND METHODS

Data were merged from 2551 eligible patients on NCCTG 79-47-51 (n = 200), NCCTG 86-47-51 (n = 656), and INT 114 (n = 1695). All patients received postoperative radiation, and 96% were randomized to receive concomitant and maintenance chemotherapy. Five-year follow-up was available in 94% of patients and 7-yr follow-up in 84%. Kaplan-Meier curves were used to estimate the distribution of overall survival (OS) and disease-free survival (DFS), and p values were derived using the log-rank test. Time to local and distant relapse was estimated using cumulative incidence methodology. Analyses were adjusted for treatment effect using Cox proportional hazards models.

RESULTS

OS and DFS were dependent on both TN stage and NT stage (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more LN+), T stage influenced 5-yr OS (T1-2, 69%; T3, 48%; T4, 38%). Three risk groups of patients were defined: (1) intermediate: T3N0, T1-2N1; (2) moderately high: T4N0, T1-2N2, T3N1; and (3) high: T3N2, T4N1, T4N2. For Group 1, 5-yr OS was 74% and 81%, and 5-yr DFS was 66% and 74%. For Group 2, 5-yr OS ranged from 61% to 69%, and for Group 3, OS ranged from 33% to 48%. Cumulative incidence rates of local relapse and distant metastases revealed similar differences by TN and NT stage, as seen in the survival analyses.

CONCLUSION

Patients with a single high-risk factor of either extension beyond the rectal wall (T3N0) or nodal involvement (T1-2N1) have improved OS, DFS, and disease control when compared to those with both high risk factors. Different treatment strategies may be indicated for intermediate- (T3N0, T1-2N1) vs. moderately high or high-risk patients in view of differential survival and rates of relapse. For future trial design, it may be preferable to perform separate studies, or a planned statistical analysis, for the "intermediate-risk" vs. the "moderately high" or "high-risk" subsets of patients.

Fatigue during preoperative chemoradiation for resectable rectal cancer

BACKGROUND

The aim of this study was to evaluate the severity and patterns of fatigue during preoperative chemoradiation therapy for locally advanced rectal cancer and determine whether there are predictors for patients who develop severe fatigue.

METHODS

Seventy-two patients with resectable rectal cancer received chemoradiation (total radiation dose, 45 gray/25 fractions to the pelvis; continuous infusion of 5-fluorouracil [300 mg/m(2)]). The Brief Fatigue Inventory (BFI), a measure that categorizes fatigue severity on a 0-10 scale, was administered weekly during treatment. Severe fatigue was defined as 7-10 on the "worst level of fatigue" item. Demographics, disease information, toxicities, and blood counts were collected. Descriptive statistics, repeated measure analysis of variance, and multiple regression were used to examine fatigue and its correlates.

RESULTS

Fatigue increased in 67% of patients during chemoradiation (CTX/XRT). The mean fatigue score increased from 3.16 before treatment to 4.62 at the end of treatment. A significant linear trend suggested that fatigue progressively got worse during CTX/XRT (F = 16.497, P < 0.001). However, 18% of patients experienced severe fatigue before CTX/XRT; this was predicted by uncontrolled pain (r(2) = 0.321; F = 16.52; P < 0.001). During CTX/XRT, uncontrolled diarrhea was the only predictor for increased fatigue (r(2) = 0.182; F = 7.77; P < 0.01). Approximately one-third of patients had severe fatigue, which impaired their function at the end of CTX/XRT.

CONCLUSIONS

Preoperative chemoradiation therapy for patients with rectal cancer was associated with progressive fatigue during therapy. Based on identified predictors for fatigue, more active pain management before CXT/XRT and bowel management during CTX/XRT might reduce cancer-related fatigue in these patients.

Improved overall survival among responders to preoperative chemoradiation for locally advanced rectal cancer

The aim of this study was to determine if the response to preoperative radiation and chemotherapy with continuous infusion 5-fluorouracil (5-FU) was predictive for survival among patients with locally advanced rectal cancer. Preoperative chemoradiation (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-FU (300 mg/m2/day) was given to 117 patients. The pretreatment stage distribution, as determined by endorectal ultrasound (u), included uT2N0 in 2%, uT3N0 in 47%, uT3N1 in 49%, and uT4N0 in 2% of cases; endorectal ultrasound was not performed in 13% of cases (15 patients). Approximately 6 weeks after completion of CTX/XRT, surgery was performed. Adjuvant chemotherapy, consisting of 400 to 425 mg/m2 of 5-FU plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for 4 to 6 cycles after surgical resection. Among the 74 patients treated with adjuvant chemotherapy, the preoperative stage of disease was 31 with T3N0 and 43 T3N1. Median follow-up was 46 months (range 2 to 89 months). The pathologic tumor stages were Tis-2N0 in 26%, T2N1 in 5%, T3N0 in 21%, T3N1 in 15%, T4N0 in 5%, and T4N1 in 1%; a complete response (CR) to preoperative CTX/XRT was pathologically confirmed in 32 (27%) of patients. Tumor down-staging occurred in 72 (62%) cases. A sphincter-saving procedure (SP) was possible in 59% of patients. The median DFS and overall survival rates for responders were 46 months and 47 months, respectively; for non-responders these outcome measures were 38 months and 41 months, respectively. Log-rank analysis showed that the distant metastatic-free survival rates improved with any response to CTX/XRT (p < 0.00001), CR to CTX/XRT (p < 0.009) and SP (p < 0.012). Likewise, these parameters also significantly influenced DFS rates (CTX/XRT p < 0.00001; CR p < 0.006; and SP p < 0.008). Control of pelvic disease was influenced by clinical size (p < 0.002) and SP (p < 0.016) on univariate analysis. On multivariate analysis only clinical size (p < 0.002) continued to be a significant factor for local control. Factors on multivariate analysis that resulted in significant improvements in cancer-specific survival included any response to preoperative CTX/XRT (p < 0.017) and administration of adjuvant chemotherapy (p < 0.034). Any response to preoperative CTX/XRT improved distant metastatic-free and disease-free survival rates. Multivariate analysis confirmed that a response to preoperative CTX/XRT predicted for improvements in overall survival among patients with locally advanced rectal cancer. Patients who fail to respond to preoperative 5-FU based chemotherapy given concomitantly with radiation have higher rates of distant metastases with adjuvant 5-FU therapy.

Prognostic implications of response to preoperative infusional chemoradiation in locally advanced rectal cancer

BACKGROUND AND PURPOSE

To evaluate the influence of response to preoperative infusional chemoradiation on outcome parameters among patients with locally advanced rectal cancer.

MATERIALS AND METHODS

Preoperative chemoradiotherapy, 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil (300 mg/m2 per day), was given to 117 patients. As determined by pretreatment endorectal ultrasound (EUS), 96% of cases were Stage T3, and 51% had EUS evidence of perirectal adenopathy. Surgery was performed approximately 6 weeks after chemoradiation therapy. Postoperatively adjuvant systemic therapy, consisting of 400-425 mg/m2 of 5-fluorouracil plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for six cycles. Outcome parameters of local control (LC), freedom from distant metastases (DMC), disease-free survival (DFS) and cancer specific survival (CSS) were evaluated relative to primary tumor characteristics.

RESULTS

The final post-treatment pathological tumor stages were complete response in 27%, Tis-2 N0 in 26%, T2 N1 in 5%, T3 N0 in 21%, T3 N1 in 15%, T4 N0 in 5% and T4 N1 in 1%. Down-staging occurred in 61% of cases. The pretreatment primary tumor size only influenced rates of local control (P < 0.03) and had no other influence on outcome parameters. Pretreatment evidence of perirectal lymph node involvement had no impact on outcome parameters. Pathologic evidence of nodal involvement did affect DMC (P < 0.002) and DFS (P < 0.003). Pathologic evidence of response did influence freedom from the development of distant metastases (P < 0.004). On pairwise analysis this relationship held only when responders were compared to non-responders. No difference was observed based on the level of downstaging at the primary tumor. Correspondingly, DFS was improved when non-responders were compared to downstaged patients (P < 0.01). Response to preoperative chemoradiation failed to affect rates of LC or CSS. For the group as a whole, adjuvant chemotherapy improved only CSS (P < 0.03). Adjuvant chemotherapy was given to 74 patients, 36 of whom had responded to preoperative chemoradiation. Improvements were only seen in DFS (P < 0.03) when down-staged patients were compared to the non-responders who received adjuvant chemotherapy. In addition, the DFS rates were lower in the non-responder group who received adjuvant chemotherapy even when they were compared to down-staged patients who did not receive adjuvant chemotherapy (P < 0.04).

CONCLUSION

Consistent with other reports, disease free survival and subsequent development of distant metastases is reduced in the more than 60% of patients who respond to preoperative infusional chemoradiation. Evidence of response appears more significant than the degree of response. At present, no impact is seen on cancer specific survival rates. Consideration should be given for strategies that base selection of subsequent adjuvant chemotherapy on response to preoperative chemoradiation.

Indications for and results of combined modality treatment of colorectal cancer

Combined modality chemoirradiation is commonly used as a component of treatment in combination with maximum resection for both high-risk resectable and locally advanced primary or recurrent rectal cancers. With surgically resected but high-risk rectal cancers, postoperative chemoirradiation has been shown to improve both disease control (local and distant) and survival (disease-free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health (NIH) Consensus Conference on Adjuvant treatment for patients with rectal and colon cancers. Subsequent intergroup trials are being conducted to help define optimal combinations of postoperative chemoirradiation for resected high-risk rectal cancers and to test sequencing issues of preoperative versus postoperative chemoirradiation. With locally unresectable primary or recurrent colorectal cancers, standard therapy with surgery, external beam irradiation (EBRT) and chemotherapy is often unsuccessful. When intraoperative electron irradiation (IOERT) is combined with standard treatment, local control and survival appear to be improved in separate analyses from the Mayo Clinic and the Massachusetts General Hospital (MGH). However, routine use of systemic therapy is also needed as a component of treatment, in view of high rates of systemic failure.