Clinical outcome in patients with complete pathologic response (pT0) to preoperative irradiation/chemo-irradiation operated for locally advanced or locally recurrent rectal cancer.

BACKGROUND

The importance of pT0 stage after preoperative radiation/chemoradiation is unclear.

METHODS

Four hundred and nineteen patients had preoperative irradiation (46-50 Gy/2 Gy fractions) for primary locally advanced (PLA) or locally recurrent (LR) rectal cancer. 141 PLA and 65 LR cases with R0 resections/M0 stage are studied. Two of the pT0 PLA patients had also been given sensitizing chemotherapy and two pT0 in the LR group had received pelvic hyperthermia as well.

RESULTS

pT0 was achieved in 7% of 229 PLA and 8% of 190 LR patients. For the PLA group, actuarial 5-year survival of pT0 was 90% versus 53% for the pT > 0 group. The difference was statistically significant. At five years local recurrence was zero in pT0 patients versus 23% in pT > 0 (not significant). For the LR groups 5-year-survival was 62% for pT0 versus 45% for the other pT-stages, local recurrence was 17 and 35% respectively (not significant). The seemingly better results for pT0 cases of PLA cancers versus the LR ones did not reach statistical significance.

CONCLUSION

pT0 after preoperative irradiation is associated with improved survival for pT0 cases of PLA. Our studies on pT0 LR was suggestive of an improvement in this group as well.