Reduced radiation dose for elective nodal irradiation in node-negative anal cancer: back to the roots?

Treatment results for patients with squamous-cell carcinoma of the anus, a single institution retrospective analysis

Background and purpose

To gain insight into the treatment outcomes for anal cancer a retrospective analysis was performed with a special emphasis on trends in outcome and toxicities over time and on treatment of elderly patients.

Materials and methods

Medical records of 98 consecutive patients with squamous cell carcinoma of the anus of all stages treated with curative intent between 01-01-2009 and 31-12-2018 were analyzed with follow up until 31-12-2020. Standard tumor and pathological lymph node dose were 59.4 Gy (median 59.4 Gy, range 59.4–70 Gy) or 60 Gy (no deviation from intended dose), elective nodal regions were treated with 45 Gy (no deviations). Radiotherapy techniques in this period evolved from 3D-conformal to IMRT and VMAT. In 23 patients electron beams were used.

Results

Median age was 63 years (range 41–88), the majority of patients were female (60%). Twenty three patients were > 75 years old. The TNM stages were I, II, IIIA, and IIIB in 18%, 40%, 15% and 27%, 58% of patients had N0 status. Concurrent mitomycin C and 5-fluoruracil-based chemotherapy was given in 63 patients (64%). Five-year overall survival (OS), disease free survival (DFS), locoregional control (LRC) and colostomy free survival (CFS) were 71%, 80%, 82%, and 82% for the whole group. Results in patients > 75 years of age were not statistically different from those in younger patients. With the introduction of more conformal techniques DFS did not change and toxicities decreased.

Conclusion

Real word treatment outcomes per disease stage were in line with what is reported in literature. Older patients should also be offered treatment with curative intent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02049-8.

What factors are associated with the poor prognosis of anal adenocarcinoma compared with low-lying rectal adenocarcinoma based on a population analysis: A propensity score matching study

PURPOSE

Anal adenocarcinoma (AA) represents a rare condition, and little is known about the predictive factors of the outcomes or the optimal TNM staging system for curable AA. Using population-based data, we preliminarily sought to determine the prognostic factors and evaluate the existing T and N staging criteria of AA.

METHODS

We analyzed the Surveillance, Epidemiology, and End Results 18 database to identify patients 20-80 years old who were diagnosed with AA or rectal adenocarcinoma (RA) and underwent abdominal perineal resection between 2004 and 2012. The difference between Kaplan-Meier survival curves was estimated by a log-rank test. A Cox proportional hazard regression model was used to adjust the effects of other covariates on survival in the propensity score-matched cohort, including age, gender, race, marital status, histology, grade of differentiation, tumor size, number of positive lymph nodes, radiotherapy, and chemotherapy.

RESULTS

Compared to patients with RA, patients with AA had a worse CSS after controlling for other covariates (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.25-3.07; P<0.01). For AA, the increasing tumor size (2-5 cm: HR, 0.62; 95% CI, 0.29-1.32; P>0.05; >5 cm: HR, 1.01; 95% CI, 0.49-2.07; P>0.05) had no significant influence on survival. The number of positive lymph nodes (1-3: HR, 2.93; 95% CI, 1.55-5.53; P<0.01; ≥4: HR, 4.24; 95% CI, 2.08-8.62; P<0.01) significantly influenced survival.

CONCLUSIONS

AA confers a worse prognosis than RA does. The T staging criteria of anal carcinoma, dominated by tumor size, seem to be invalid for AA, while the number of positive lymph nodes is a prognostic factor.

Management of locally advanced anal canal carcinoma with intensity-modulated radiotherapy and concurrent chemotherapy

The best curative option for locally advanced (stages II-III) squamous-cell carcinomas of the anal canal (SCCAC) is concurrent chemo-radiotherapy delivering 36-45 Gy to the prophylactic planning target volume with an additional boost of 14-20 Gy to the gross tumor volume with or without a gap-period between these two sequences. Although 3-dimensional conformal radiotherapy led to suboptimal tumor coverage because of field junctions, this modality remains a standard of care. Recently, intensity-modulated radiotherapy (IMRT) techniques improved tumor coverage while decreasing doses delivered to organs at risk. Sparing healthy tissues results in fewer severe acute toxicities. Consequently, IMRT could potentially avoid a gap-period that may increase the risk of local failure. Furthermore, these modalities reduce severe late toxicities of the gastrointestinal tract as well as better functional conservation of anorectal sphincter. This report aims to critically review contemporary trends in the management of locally advanced SCCAC using IMRT and concurrent chemotherapy.

Anal adenocarcinoma requires prophylactic inguinal nodal treatment: Results from a single Chinese institution

Background: Literature pertaining to prophylactic inguinal nodal treatment for anal adenocarcinoma in China is scarce.

Methods: In this retrospective study, we analyzed 126 patients from 1965 to 2015. Among these, 67 patients received surgery only, 18 patients received chemoradiotherapy only, 27 patients received a combination of both, and the remaining 14 patients received palliative treatment.

Results: The median follow up period was 30 months. The 1-year, 3-year, and 5-year overall survival rates were 85.8%, 62.5%, and 43.4%, respectively. The 5-year overall survival was 46.9% for patients with negative inguinal lymph nodes and 19.1% for patients with positive inguinal lymph nodes (p=0.007). The overall 5-year inguinal node relapse-free survival was 83.0%. The 5-year inguinal node relapse-free survival was 87.5% for stage I, 86.9% for stage II, and 76.5% for stage III cancers. Among those with negative inguinal nodes, the 5-year inguinal node relapse-free survival was 85.7% for negative regional lymph nodes and 75.4% for positive regional lymph nodes (p=0.089).

Conclusion: Inguinal lymph node is a high-risk subclinical area. Prophylactic inguinal nodal treatment is necessary for patients with anal adenocarcinoma irrespective of positive or negative inguinal lymph nodes.