Identification of low-risk cases of invasive endocervical adenocarcinoma with Silva pattern-based classification: a systematic review and -analysis.

Objective: We aimed to describe the discriminatory ability of the Silva pattern-based classification system for invasive endocervical adenocarcinoma (EAC) in predicting risks of lymph node (LN) metastasis, recurrence, and death.

Method: We systematically searched PubMed, Scopus, and Embase through 2024 for manuscripts describing patients with EAC by Silva pattern-based classification. We included studies reporting outcomes of LN metastasis, recurrence, or death by Silva pattern. Random-effects -analysis was used to summarize binomial proportions and compare outcomes between groups.

Results: We identified 19 studies including 2998 patients (20.8 % pattern A, 23.1 % pattern B, 54.1 % pattern C). Silva pattern A cases showed a significantly lower risk of LN metastasis (3/509; 0.6 %) than pattern B (6.1 %; OR = 0.33, 95 %CI 0.16-0.67) or pattern C (22.0 %; OR = 0.09; 95 %CI 0.05-0.16). Across 5 studies limited to stage I disease, there were no Silva pattern A cases with LN metastasis, recurrence, or death. Among 11 studies reporting on recurrence and death, Silva pattern A cases had distinctly low risk of 0.3 % for both outcomes, including a significantly lower risk of recurrence (OR = 0.15, 95 %CI 0.06-0.34) and death (OR = 0.21, 95 %CI 0.09-0.50) versus patterns B/C. Silva pattern B cases showed significantly lower risk of all outcomes compared with pattern C.

Conclusions: We demonstrate that Silva classification is highly predictive of oncologic outcomes for EAC, with patterns A, B, and C showing distinct low, intermediate, and high risk profiles. The low risk profile of pattern A may justify future prospective study of surgical and adjuvant treatment de-escalation from the current standard of care, while pattern C cases may warrant consideration of adjuvant treatment escalation.