Long-course preoperative chemoradiation versus 5 × 5 Gy and consolidation chemotherapy for clinical T4 and fixed clinical T3 rectal cancer: long-term results of the randomized Polish II study

BACKGROUND

This trial evaluated whether preoperative short-course radiotherapy and consolidation chemotherapy (CCT) were superior to chemoradiation in rectal cancers with clinical (c)T4 or fixed cT3. Previously, we reported early results showing no differences in the radical surgery rate (primary end point). In the short-course/CCT group, we observed lower acute toxicity of preoperative treatment and better overall survival (OS). We updated results to determine whether the benefit in OS was sustained and to evaluate late complications.

PATIENTS AND METHODS

Patients with cT4 or fixed cT3 rectal cancer were randomized either to preoperative 5 × 5 Gy and three cycles of FOLFOX4 or to chemoradiation (50.4 Gy with bolus 5-Fu, leucovorin and oxaliplatin).

RESULTS

Patients (N = 515) were eligible for analysis, 261 in the short-course/CCT group and 254 in the chemoradiation group. The median follow-up was 7.0 years. The difference in OS was insignificant [hazard ratio (HR) 0.90; 95% confidence interval (CI) 0.70-1.15; P = 0.38). However, the difference in early OS favouring short-course/CCT previously reported was observed again, being 9% at 3 years (95% CI 0.5% to 17%). This difference disappeared later; at 8 years OS was 49% in both groups. There was no difference in disease-free survival (HR 0.95; 95% CI 0.75-1.19; P = 0.65) at 8 years 43% versus 41% in the short-course/CCT group versus the chemoradiation group, respectively. The corresponding values for cumulative incidences of local failure and distant metastases did not differ and were HR = 1.08, 95% CI 0.70-1.23, P = 0.60, 35% versus 32% and HR = 1.10, 95% CI 0.68-1.23, P = 0.54, 36% versus 34%, respectively. The rate of late complications was similar (P = 0.66), grade 3+ being 11% versus 9% in the short-course/CCT group versus the chemoradiation group, respectively.

CONCLUSION

The superiority of preoperative short-course/CCT over chemoradiation was not demonstrated.

CLINICAL TRIAL NUMBER

The trial is registered as ClinicalTrials.gov number NCT00833131.

Long-course oxaliplatin-based preoperative chemoradiation versus 5 × 5 Gy and consolidation chemotherapy for cT4 or fixed cT3 rectal cancer: results of a randomized phase III study

BACKGROUND

Improvements in local control are required when using preoperative chemoradiation for cT4 or advanced cT3 rectal cancer. There is therefore a need to explore more effective schedules.

PATIENTS AND METHODS

Patients with fixed cT3 or cT4 cancer were randomized either to 5 × 5 Gy and three cycles of FOLFOX4 (group A) or to 50.4 Gy in 28 fractions combined with two 5-day cycles of bolus 5-Fu 325 mg/m(2)/day and leucovorin 20 mg/m(2)/day during the first and fifth week of irradiation along with five infusions of oxaliplatin 50 mg/m(2) once weekly (group B). The protocol was amended in 2012 to allow oxaliplatin to be then foregone in both groups.

RESULTS

Of 541 entered patients, 515 were eligible for analysis; 261 in group A and 254 in group B. Preoperative treatment acute toxicity was lower in group A than group B, P = 0.006; any toxicity being, respectively, 75% versus 83%, grade III-IV 23% versus 21% and toxic deaths 1% versus 3%. R0 resection rates (primary end point) and pathological complete response rates in groups A and B were, respectively, 77% versus 71%, P = 0.07, and 16% versus 12%, P = 0.17. The median follow-up was 35 months. At 3 years, the rates of overall survival and disease-free survival in groups A and B were, respectively, 73% versus 65%, P = 0.046, and 53% versus 52%, P = 0.85, together with the cumulative incidence of local failure and distant metastases being, respectively, 22% versus 21%, P = 0.82, and 30% versus 27%, P = 0.26. Postoperative and late complications rates in group A and group B were, respectively, 29% versus 25%, P = 0.18, and 20% versus 22%, P = 0.54.

CONCLUSIONS

No differences were observed in local efficacy between 5 × 5 Gy with consolidation chemotherapy and long-course chemoradiation. Nevertheless, an improved overall survival and lower acute toxicity favours the 5 × 5 Gy schedule with consolidation chemotherapy.

CLINICAL TRIAL NUMBER

The trial is registered as ClinicalTrials.gov number NCT00833131.