Treatment overview:

  • chemoradiation
    • addition of chemotherapy (5-FU plus mitomycin) to radiation therapy may reduce local failure and colostomy rates
    • drugs of choice - fluorouracil (Adrucil, 5-FU) plus mitomycin (Mutamycin)
    • addition of mitomycin to chemoradiation with 5-FU may improve colostomy-free survival
    • cisplatin may be associated with less hematologic toxicity than mitomycin as part of chemoradiation but increased risk for colostomy 
    • assessment of response to chemoradiation recommended at 6-8 weeks
  • radiotherapy
    • three-dimensional conformal radiotherapy (3D-CRT) may improve survival and freedom from relapse compared to conventional radiotherapy
    • external beam radiation without chemotherapy reported to be effective for T1 and T2 lesions in case series
    • pelvic irradiation associated with increased risk of pelvic fracture in older women
  • abdominoperineal resection (APR) considered salvage therapy for persistent or recurrent disease after chemoradiation

Medications:

  • drugs of choice according to The Medical Letter
    • drugs of choice - fluorouracil (Adrucil, 5-FU) plus mitomycin (Mutamycin)
    • alternative - cisplatin (Platinol) plus fluorouracil (Adrucil, 5-FU)
  • addition of chemotherapy (5-FU plus mitomycin) to radiation therapy may reduce local failure and colostomy rates
    • based on 2 randomized trials without blinding
    • UKCCCR trial
      • 585 patients aged 26-88 years with epidermoid anal cancer were randomized to chemoradiation (radiation plus mitomycin plus 5-FU) vs. radiotherapy alone and followed for median 42 months
        • external beam radiation with 45 Gy as central axis dose given for 4-5 weeks
        • chemotherapy given with first course of radiotherapy
          • initial chemotherapy was 5-FU (1,000 mg/m2 IV for 4 days or 750 mg/m2 for 5 days) plus mitomycin (12 mg/m2 IV given on day 1 of first course of radiotherapy)
          • subsequent chemotherapy was 5-FU (same dose) without mitomycin during final week of first radiotherapy course
      • 562 (96%) patients who had ≥ 6 weeks of treatment were analyzed
      • comparing chemoradiation vs. radiation alone at 3 years
        • 39% vs. 61% local failure (p < 0.0001, NNT 5)
        • 65% vs. 58% overall survival (not significant)
    • EORTC trial
      • 110 patients with locally advanced anal cancer were randomized to chemoradiation (5-FU plus mitomycin plus radiation) vs. radiation alone and followed for median 42 months
        • radiotherapy consisted of 45 Gy given in 5 weeks (daily dose 1.8 Gy), additional treatment given at 6 weeks if partial (20 Gy) or complete (15 Gy) response
        • chemotherapy (given with first course of radiotherapy) consisted of fluorouracil 750 mg/m2 IV continuously on days 1-5 and 29-33 plus mitomycin 15 mg/m2 as single dose on day 1
      • comparing chemoradiation vs. radiation alone
        • 80% vs. 54% had complete remission
        • 68% vs. 50% estimated locoregional control at 5 years (p = 0.02, NNT 6)
        • 72% vs. 40% estimated colostomy-free rate (p = 0.002, NNT 3)
        • 58% vs. 54% overall survival (not significant)
      • no significant differences in severe side effects but anal ulcers more frequent with combination therapy
  • addition of mitomycin to chemoradiation with 5-FU may improve colostomy-free survival
    • based on randomized trial with allocation concealment and blinding not stated
    • 310 patients with anal canal cancer were given chemoradiation with 5-FU (1,000 mg/m2 on days 1 and 29) plus radiotherapy (45-50 Gy over 5 weeks) and then randomized to mitomycin (10 mg/m2 on days 1 and 29) vs. no additional treatment and followed for median 3 years
    • patients with residual tumor had salvage treatment with radiation 9 Gy, 5-FU, and cisplatin 100 mg/m2
    • 291 patients (94%) were analyzed
    • comparing chemoradiation with vs. without mitomycin at 4 years
      • 9% vs. 22% colostomy rate (p = 0.002, NNT 8)
      • 71% vs. 59% colostomy-free survival (p = 0.014, NNT 9)
      • 73% vs. 51% disease-free survival (p = 0.0003, NNT 5)
      • no significant differences in overall survival
    • grade 4-5 toxicity occurred in 23% of patients with mitomycin vs. 7% without (p < 0.001, NNH 7)
  • cisplatin may be associated with less hematologic toxicity than mitomycin as part of chemoradiation but increased risk for colostomy
    • based on randomized trial without blinding
    • 682 patients with anal cancer were given radiation and were randomized to 5-FU plus cisplatin vs. 5-FU plus mitomycin
      • 5-FU plus cisplatin group treated with
        • 5-FU 1,000 mg/m2 daily (days 1-4, 29-32, 57-60, 85-88)
        • cisplatin 75 mg/m2 (days 1, 29, 57, 85)
        • radiation 45-59 Gy starting on day 57
      • 5-FU plus mitomycin group treated with
        • 5-FU 1,000 mg/m2 daily (days 1-4, 29-32)
        • mitomycin 10 mg/m2 bolus (days 1, 29)
        • radiation 45-59 Gy
    • median follow-up 2.51 years
    • 644 (94.4%) patients analyzed
    • comparing chemoradiation with cisplatin vs. chemoradiation with mitomycin
      • 42% vs. 61% had grade 3-4 hematologic toxicity (p = 0.001, NNT 6 favoring cisplatin)
      • 16% vs. 10% had colostomy at 3 years (p = 0.02, NNH 17)
      • 19% vs. 10% had colostomy at 5 years (p = 0.02, NNH 11)
      • 61% vs. 67% disease-free survival at 3 years (not significant)
      • 54% vs. 60% disease-free survival at 5 years (not significant)
      • 76% vs. 84% overall survival at 3 years (not significant)
      • 70% vs. 75% overall survival at 5 years (not significant)

Surgery:

  • abdominoperineal resection (APR)
    • results in permanent end colostomy
    • current recommended role is salvage therapy for persistent or recurrent disease following chemoradiation in patients who are not candidates for salvage chemoradiation

Other management:

  • three-dimensional conformal radiotherapy (3D-CRT) may improve survival and freedom from relapse compared to conventional radiotherapy
    • based on prospective cohort study
    • 62 consecutive patients with anal cancer had 3D-CRT 54 Gy in 30 fractions continuously and were compared to 60 historical controls having conventional radiotherapy with median 54 Gy in split course
    • all patients had concurrent chemotherapy with 5-fluorouracil plus either mitomycin-C or cis-platinum
    • comparing 3D-CRT vs. conventional radiation at 5 years
      • 80.7% vs. 53.9% overall survival (p = 0.017, NNT 4)
      • 70.2% vs. 46.1% freedom from relapse (p = 0.016, NNT 4)
      • 85.1% vs. 61.1% actuarial local control (p = 0.005, NNT 5)
  • external radiation therapy without chemotherapy reported to be effective for T1 and T2 lesions
    • based on 3 case series
    • case series of 305 patients with cancer of anal canal
      • 305 patients with anal cancer had curative-intent radiotherapy (median dose 45 Gy) and were followed for mean 103 months
        • 279 patients had EBRT 20 Gy boost after rest period of 4-6 weeks
        • 17 had interstitial (192)Ir brachytherapy boost after rest period of 4-6 weeks
        • 7 patients had only 1 course of EBRT
        • 2 patients had interstitial (192)Ir brachytherapy only
        • 19 patients had concomitant chemotherapy with 5-FU plus either cisplatin or mitomycin-C
      • local tumor clinical response rates at end of radiotherapy
        • 96% for T1 tumors
        • 87% for T2 tumors
        • 79% for T3 tumors
        • 44% for T4 tumors
      • 74% disease-free survival at 10 years
      • factors associated with disease-free survival were
        • interval between 2 courses of radiotherapy
        • pretreatment anal function score
        • clinical compete response after radiotherapy
    • case series of 72 patients with cancer of anal canal
      • all patients treated with external beam radiation (commonly 5,000 centigray over 4 weeks)
      • 5-year outcomes
        • 66% actuarial survival
        • 78% disease-specific survival (71% T1, 88% T2, 41% T3, 42% T4)
      • 17 patients (24%) had local recurrence
      • 53 patients (74%) retained anal function
      • 6 patients (8%) had severe late complications
    • case series of 18 patients with cancer of anal canal
      • all had radiation 45-50 Gy in 25-28 fractions, 16 had additional radiation increasing total dose to 55-67 Gy
      • follow-up ranged from 2.5-11.2 years
      • 94% projected survival at 5 years
      • 100% projected freedom from local recurrence at 5 years
      • no patient required permanent colostomy or had permanent sphincter function loss
  • chemotherapy plus external beam radiation followed by interstitial implant reported to have 84% loco-regional control in patients with T3 and T4 anal cancer
    • based on case series
    • 31 patients with T3 or T4 anal cancer had external beam radiation 30 Gy plus 5-FU plus mitomycin-C followed by interstitial (192)Ir implant boost (median implant dose 31.3 Gy at 0.5 cm delivered at mean 0.52 Gy/hour)
    • 6 patients had local persistence
    • 4 developed local recurrence
    • 8 patients had abdominoperineal resection (APR)
    • 84% local regional control after initial treatment and APR
  • pelvic irradiation associated with increased risk of pelvic fracture in older women
    • based on retrospective cohort study
    • 6,428 women > 65 years old with pelvic malignancies included 556 women with anal cancer, 1,605 with cervical cancer and 4,267 with rectal cancer
    • rates of pelvic fracture in women who had pelvic irradiation vs. women who did not have pelvic irradiation
      • 14% vs. 5% in women with anal cancer
      • 7% vs. 5% in women with cervical cancer
      • 9% vs. 9% in women with rectal cancer
    • cumulative 5-year fracture rate (after adjusting for length of follow-up) in women who had pelvic irradiation vs. women who did not have pelvic irradiation
      • 14% vs. 7.5% in women with anal cancer
      • 8.2% vs. 5.9% in women with cervical cancer
      • 11.2% vs. 8.7% in women with rectal cancer