Outcomes with anti-EGFR monoclonal antibodies in metastatic and recurrent anal squamous cell carcinoma

ABSTRACT

Objectives

Metastatic squamous cell carcinoma anal cancer (SCCA) is rare. Prospective data recommends front-line platinum doublet combinations and second-line anti-programmed death-1 therapy. Standard therapy beyond these treatments are currently unknown. We evaluated anti-EGFR monoclonal antibody (mAb) outcomes in metastatic SCCA.

Methods

Metastatic SCCA patients given anti-EGFR mAb from Oct 2011-May 2018 were included. Primary endpoints included best response, progression-free survival, and overall survival.

Results

56 patients were evaluated with a median of one prior therapy. Most patients (~90%) received anti-EGFR mAbs with chemotherapy. Response rate (any response) was 41%. Median PFS was 4.3 months with a median OS of 16 M. Seven patients with disease control proceeded onto maintenance therapy (anti-EGFR mAb ± a fluoropyrimidine) with a median PFS of 13.8 M. Next generation sequencing of 16 pts (28%) showed 4 pts had a PIK3CA mutation with 3 of these 4 patients demonstrating progression on initial restaging.

Conclusion

Our analysis suggests anti-EGFR mAb therapy with chemotherapy provides clinical benefit in previously treated metastatic SCCA. Our maintenance therapy and the role of PIK3CA MT outcomes were thought-provoking.

Expert Opinion

Metastatic SCCA patients have limited options; therefore, anti-EGFR mAbs may provide benefit in the treatment armamentarium and should be further explored.

KEYWORDS:

• Cetuximab
• panitumumab
• anus neoplasms
• epidermal growth factor
• anal cancer

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

J.E. Rogers: Conceptualization, design, formal analysis, data curation, investigation, methodology, resources, supervision, manuscript writing, final approval. A.A. Jácome: Conceptualization, formal analysis, statistics, manuscript writing, final approval. A. Ohinata: Resources, provision of study materials or patients, manuscript writing, final. R. Wolff: Resources, provision of study materials or patients, manuscript writing, final approval. V.K. Morris: Resources, provision of study materials or patients, manuscript writing, final approval. B. Johnson: Resources, provision of study materials or patients, manuscript writing, final approval. A. Mehdizadeh: Resources, provision of study materials or patients, manuscript writing, final approval. N.D. Rothschild: Resources, provision of study materials or patients, manuscript writing, final approval. SU Ahmed: Resources, provision of study materials or patients, manuscript writing, final approval. JL Guerra: Resources, provision of study materials or patients, manuscript writing, final approval. C. Eng: Conceptualization, design, resources, provision of study materials or patients, investigation, methodology, supervision, manuscript writing, final approval.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.