Oncologic outcomes for invasive squamous cell carcinoma with a clinically resolved biopsy site managed by watchful waiting: A retrospective cohort study

Background: Treatment of cutaneous squamous cell carcinoma largely involves surgical excision. Few studies have examined oncologic outcomes of tumors managed by watchful waiting when the lesion appears resolved after the biopsy site has healed.

Objective: To describe oncologic outcomes for patients diagnosed with cutaneous squamous cell carcinoma that was determined clinically resolved at follow-up and subsequently managed by watchful waiting.

Methods: This retrospective cohort included pathology proven cases of cutaneous squamous cell carcinoma occurring from 1/1/2013 to 4/31/2023. Each required documented clinical resolution more than 4 weeks after biopsy, management by watchful waiting, and at least 12 months of follow-up.

Results: Of 148 tumors managed by watchful waiting, there were two cases of local recurrence, and no cases of nodal metastasis, distant metastasis, or disease specific death. Log-rank test found significant risk of recurrence in immunocompromised participants (HR=12.87, p=0.0193) and those with rheumatologic disease (HR=16.18, p=0.0075).

Limitations: Retrospective, single-center design.

Conclusion: The recurrence rate in this cohort compares favorably to reported recurrence rates for surgically managed cutaneous squamous cell carcinoma. In select cases, watchful waiting may be a reasonable management option for low-risk lesions that appear clinically resolved after healing of the biopsy site.