Table 2.
Tumor characteristics, treatment characteristics, and response for patients treated with radiation therapy for de novo rectal and anal cancers after prior prostate RT.
| Characteristics | Rectal cancer* (n=17) frequency (%)/median (range) | Anal cancer (n=9) frequency (%)/median (range) | |||
|---|---|---|---|---|---|
| AJCC Stage | Stage I | 2 (11.76%) | 0 | ||
| Stage IIA | 6 (35.29%) | 3 (33.33%) | |||
| Stage IIB | 0 | 1 (11.11%) | |||
| Stage IIC | 1 (5.88%) | NA | |||
| Stage IIIA | 0 | 2 (22.22%) | |||
| Stage IIIB | 2 (11.76%) | 2 (22.22%) | |||
| Stage IIIC | 3 (17.65%) | 1 (11.1%) | |||
| Recurrent | 3 (17.65%) | 0 | |||
| Size (MRI) in cm | 3.2 (1.5, 8.0) | 3 (1.2, 6.5) | |||
| Location | anterior | 8 (53.33%) | 1 (12.5%) | ||
| posterior | 6 (40%) | 4 (50%) | |||
| lateral | 1 (6.67%) | 3 (37.5%) | |||
| Anal sphincter involvement | 5 (33.33%) | 7 (77.78%) | |||
| Prostate/bladder/SV or levator ani involvement (T4) | 5 (31.25%) | 1 (11.11%) | |||
| RT modality | EBRT | 13 (76.47%) | 9 (100%) | ||
| Brachytherapy alone | 4 (23.53%) | 0 | |||
| Brachytherapy boost after EBRT | 0 | 2 (22.22%) | |||
| RT treatment group | Definitive EBRT | 9 (52.94%) | 6 (66.67%) | ||
| Palliative | 4 (23.53%) | 0 | |||
| Combo brachy +EBRT | 0 | 2 (22.22%) | |||
| BID | 4 (23.53%) | 1 (11.11%) | |||
| RT brachytherapy dose (cGy) | 500/1 | 1 (25%) | 0 | ||
| 1200-1500/3 | 1 (25%) | 1 (50%) | |||
| 1500-1750/1 | 2 (50%) | 0 | |||
| 1950/3 | 0 | 1 (50%) | |||
| RT EBRT dose (cGy) | 4500 (3000, 5040) | 5000 (2520,5000) | |||
| RT EBRT fractions | 25 (5, 28) | 25 (20, 25) | |||
| Two courses of anorectal RT after prior prostate RT | 1 (5.88%) with a dose of 3000 cGy/5 fractions given twice | 0 | |||
| Chemotherapy concurrent (5FU based) | 11 (64.71%) | 8 (88.89%) | |||
| Chemotherapy adjuvant/neoadjuvant | 10 (58.82%) (70% FOLFOX and 30% 5FU) |
2 (22.22%) (50% MMC+5FU and 50% Cisplatin+5FU |
|||
| Clinical response | stable | 1 (6.7%) | 0 | ||
| partial response | 9 (60%) | 3 (33.33%) | |||
| complete response | 5 (33.33%) | 6 (66.7%) | |||
| missing | 2 | 0 | |||
| Pathological response: pTN | I | 1 (14.29%) | NA | ||
| IIA | 3 (42.86%) | NA | |||
| IIB | 1 (14.29%) | NA | |||
| IIIB | 1 (14.29%) | NA | |||
| IIIC | 1 (14.29%) | NA | |||
| LVI positive | 3 (50%) | NA | |||
| Rectal spacer | 0 | 1 (11.11%) | |||
*: median distance of 4.5 cm from the anal verge.
SV, seminal vesicles; RT, Radiation therapy; EBRT, External beam radiation therapy.