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.