Nodal status and survival in anal cancer

Prognostic factors of colostomy free survival in patients presenting with locally advanced anal canal carcinoma: A pooled analysis of two prospective trials (KANAL 2 and ACCORD 03)

BACKGROUND

To carry out a prognosis study of the prospective studies KANAL 2 and ACCORD 03 in order to highlight new prognostic factors of colostomy-free survival in patients with locally advanced anal canal carcinoma.

PATIENTS AND METHODS

KANAL 2 and ACCORD 03 were phase 2 and phase 3 multicenter trials with same inclusion criteria: anal canal squamous cell carcinoma of ≥4 cm or pelvic node involvement treated with conformal radiotherapy (45 Gy/25 fractions plus a boost) and concomitant fluorouracyl and cisplatin at weeks 1 and 5. A multivariate analysis of potential factors (patients, tumors, and treatments) was carried out through Cox proportional hazard model. Results were presented as hazard ratio (HR).

RESULTS

387 patients were included. In multivariate analysis, age over 55 years (HR = 0.62, p = 0.013), the increase of circumferential tumor spread (between 1/3 and 2/3 and more than 2/3 compared to less than 1/3) (respectively 1.97, p = 0.015 and 2.94, p < 0.001), the skin ulceration (1.57, p = 0.03), the inguinal node involvement (1,98, p < 0.001) and the total radiotherapy dose above 60 Gy (between 60 and 65 Gy (HR = 0.37, p < 0.001) and >65 Gy (HR = 0.61, p = 0.028)) were associated with colostomy-free survival.

CONCLUSION

Our study highlights new favorable prognostic factors such as circumferential tumor damage of less than two thirds, age over 55 years, dose escalation boost irradiation and possibly a total radiation dose between 60 and 65 Gy (but the BED dose depends on the overall treatment time). These results could be considered for better selection or stratification of the target population in future trials.

Anal squamous cell carcinoma - State of the art management and future perspectives

Anal squamous cell carcinoma (ASCC) is associated with infection with high-risk strains of human papilloma virus (HPV) in 70-90% of cases and a rise in incidence has been observed in the last decades. Definitive chemoradiotherapy (CRT) using 5-fluorouracil and mitomycin C constitutes the standard treatment for localized disease, but about 30% of patients do not respond or relapse locally. Phase I/II trials testing targeted agents, such as epidermal-growth-factor receptor (EGFR) inhibitors, have failed to improve clinical outcome and resulted in increased toxicities. Modern imaging methods and biomarkers, also in the context of HPV status, should be further explored to improve patient stratification. In the present review, we will discuss the current clinical evidence and future perspectives in the management of ASCC. HPV-positive ASCC is more immunogenic with a higher density of tumor infiltrating lymphocytes that correlate with better response to CRT and more favorable prognosis compared to HPV-negative tumors. Immunotherapies including immune checkpoint inhibitors have brought new hope and promising results were recently demonstrated in metastatic ASCC. The addition of immunotherapies to CRT for localized disease is tested in early phase trials, and these results could have a profound impact on the way we treat ASCC in near future. Further research and novel approaches are expected to enhance our understanding of tumor biology and immunology, and improve patient stratification and treatment adaptation in the context of personalized medicine.