Survival outcomes used to generate version 9 American Joint Committee on Cancer staging system for anal cancer

The inguinal lymph nodes as regional lymph nodes in anal canal adenocarcinomas: a nationwide database analysis in Japan

PURPOSE

To establish if it is appropriate to treat the inguinal lymph node (LN) of anal canal adenocarcinoma (ACA) as the intermediate LN according to the Japanese classification.

METHODS

The characteristics of 346 ACA patients were examined from the nationwide registry. The effect of LN dissection was evaluated using the therapeutic value index (TVI). Furthermore, the prognostic classification ability of N factors and stage was evaluated using Akaike's information criterion (AIC), the concordance index (C-index), and the 5-year overall survival (OS) rate.

RESULTS

The rate of metastasis of the inguinal LN was 7.5% and the TVI was 3.05. Evaluation using AIC and the C-index showed better results when the inguinal LN was treated as the intermediate LN. The 5-year OS rate for 66 patients with perirectal or intermediate LN metastasis, 7 with inguinal LN metastasis, and 13 with inguinal and perirectal or intermediate LN metastasis were 49.2%, 68.6%, and 47.6%, respectively. When inguinal LN metastases were treated as N3, the 5-year OS rates were 66.7% for those with T1N3 and T2N3 disease, and 49.2% for those with T3N3 disease.

CONCLUSIONS

The inguinal LN of ACA was evaluated and staged as the intermediate LN to devise an appropriate treatment strategy.

Data-driven optimization of version 9 American Joint Committee on Cancer staging system for anal cancer

INTRODUCTION

The American Joint Committee on Cancer (AJCC) staging system undergoes periodic revisions to maintain contemporary survival outcomes related to stage. Recently, the AJCC has developed a novel, systematic approach incorporating survival data to refine stage groupings. The objective of this study was to demonstrate data-driven optimization of the version 9 AJCC staging system for anal cancer assessed through a defined validation approach.

METHODS

The National Cancer Database was queried for patients diagnosed with anal cancer in 2012 through 2017. Kaplan-Meier methods analyzed 5-year survival by individual clinical T category, N category, M category, and overall stage. Cox proportional hazards models validated overall survival of the revised TNM stage groupings.

RESULTS

Overall, 24,328 cases of anal cancer were included. Evaluation of the 8th edition AJCC stage groups demonstrated a lack of hierarchical prognostic order. Survival at 5 years for stage I was 84.4%, 77.4% for stage IIA, and 63.7% for stage IIB; however, stage IIIA disease demonstrated a 73.0% survival, followed by 58.4% for stage IIIB, 59.9% for stage IIIC, and 22.5% for stage IV (p <.001). Thus, stage IIB was redefined as T1-2N1M0, whereas Stage IIIA was redefined as T3N0-1M0. Reevaluation of 5-year survival based on data-informed stage groupings now demonstrates hierarchical prognostic order and validated via Cox proportional hazards models.

CONCLUSION

The 8th edition AJCC survival data demonstrated a lack of hierarchical prognostic order and informed revised stage groupings in the version 9 AJCC staging system for anal cancer. Thus, a validated data-driven optimization approach can be implemented for staging revisions across all disease sites moving forward.

Management and staging of anal adenocarcinoma in the United States: a population-based analysis

BACKGROUND

Anal adenocarcinoma is rare with no standardized treatment regimen or staging system. Therefore, different combinations of chemotherapy, radiation, and surgery are used in management. Within the staging system, tumor stage can be based on the depth of invasion, as for rectal adenocarcinoma, or size, as in anal squamous cell carcinoma. This study aimed to analyze patterns of care and clinically available staging systems for anal adenocarcinoma using a national database.

METHODS

Adults diagnosed with anal adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results database (2004-2019). In addition, 6 different treatment regimens were identified. Stages were categorized according to the American Joint Committee on Cancer classifications of rectal adenocarcinoma and anal squamous cell carcinoma.

RESULTS

Of 1040 patients, 48% were female, the median age was 67 years, and 18% had distant metastases. Chemoradiotherapy + abdominoperineal resection was the most common treatment regimen (22%). Moreover, 5-year overall survival (OS) and disease-specific survival (DSS) were the highest for local excision only (67% and 85%) and the lowest in the alternative group (34% and 48%). After adjustment, the treatment groups that did not include surgery were associated with worse 5-year OS. In multivariable analysis, the T stage based on depth of invasion showed incrementally lower OS for T2 and T3 anal adenocarcinomas.

CONCLUSION

Omission of surgical resection in combination with chemoradiotherapy was associated with worse OS and DSS, suggesting the relevance of surgery in anal adenocarcinoma management. Prognostically, rectal staging based on depth of invasion better discriminated between T stages, indicating that providers should consider using this system in practice.

The accuracy of anal self- and companion exams among sexual minority men and transgender women: a prospective analysis

Background

Squamous cell carcinoma of the anus (SCCA) annual incidence among sexual minority men with and without HIV is 85/100,000 and 19/100,000 persons, respectively, which is significantly higher than the overall incidence (2/100,000). Incidence may also be higher in transgender women. Since SCCA tumours average ≥30 mm at diagnosis, we assessed the accuracy of individuals to self-detect smaller anal abnormalities.

Methods

Using convenience sampling, the study enrolled sexual minority men and transgender women, aged 25-81 years, in Chicago, Illinois and Houston, Texas, USA, during 2020-2022. Individuals were taught the anal self-examination and anal companion examination (ASE/ACE). Then, a clinician performed a digital anal rectal examination (DARE) before participants conducted the ASE or ACE. The sensitivity, specificity and concordance of the ASE/ACE to detect an abnormality were measured along with factors associated with ASE/ACE and DARE concordance.

Findings

Among 714 enrolled individuals, the median age was 40 years (interquartile range, 32-54), 36.8% (259/703) were living with HIV, and 47.0% (334/710), 23.4% (166/710), and 23.0% (163/710) were non-Hispanic white, non-Hispanic Black, and Hispanic, respectively. A total of 94.1% (671/713) identified as cisgendered men, and 5.9% (42/713) as gender minorities. A total of 658 participants completed an ASE and 28 couples (56 partners) completed an ACE. Clinicians detected abnormalities in 34.3% (245/714) of individuals. The abnormalities were a median of 3 mm in diameter. Sensitivity and specificity of the ASE/ACE was 59.6% (95% CI 53.5-65.7%) and 80.2% (95% CI 76.6-83.8%), respectively. Overall concordance was 0.73 (95% CI 0.70-0.76) between ASE/ACE and DARE and increased with increasing anal canal lesion size (p = 0.02). Concordance was lower when participants were older and received ASE/ACE training from a lay person rather than a clinician.

Interpretation

Sexual minority men/transgender women may self-detect SCCA when malignant lesions are much smaller than the current mean dimension at presentation of ≥30 mm.

Funding

National Cancer Institute.