Anal Cancer Medication

Updated: Sep 15, 2022
  • Author: Thomas R Dekoj, MD; Chief Editor: N Joseph Espat, MD, MS, FACS  more...
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Medication Summary

Topical medications used off-label for the treatment of anal intraepithelial neoplasia (AIN) of the anal margin include imiquimod 5% cream (Aldara) and 5-fluorouracil (5-FU) 5% (Efudex). Imiquimod cream, which can be used only for anal margin lesions, is applied three times per week at bedtime for maximum of 16 weeks. [71, 78, 79] 5-FU cream is applied twice daily for 3-6 weeks. [71, 78, 79] Close surveillance of patients is required with both these treatments.

For systemic treatment of anal cancer, intravenous 5-FU (or its oral prodrug, capecitabine) and mitomycin are used as radiosensitizing agents. 5-FU and cisplatin are used for metastatic disease.


Systemic Antineoplastic Agents

Class Summary

System agents are used adjunctively with radiation therapy or for metastatic disease.

Fluorouracil (Adrucil)

Intravenous 5-FU is used with mitomycin as a radiosensitizing agent for treatment of anal cancer. It is also used with cisplatin for metastatic disease. It is an antimetabolite that inhibits DNA synthesis during S phase by inhibition of thymidylate synthetase.


Mitomycin is used IV with 5-FU as a radiosensitizing agent for treatment of anal cancer. It acts by crosslinking DNA, and thereby prevents replication and transcription.


IV cisplatin is used with 5-FU for metastatic anal cancer. It is an alkylating agent and a platinum coordination compound that inhibits DNA synthesis; cross-links and denatures strands of DNA.

Capecitabine (Xeloda)

Fluoropyrimidine carbamate prodrug form of 5-fluorouracil (5-FU). Capecitabine itself is inactive. Undergoes hydrolysis in liver and tissues to form the active moiety (fluorouracil), inhibiting thymidylate synthetase, which in turn blocks methylation of deoxyuridylic acid to thymidylic acid. This step interferes with DNA and to a lesser degree with RNA synthesis.


Topical Antineoplastic Agents

Class Summary

Agents in this class inhibit cell growth and proliferation.

Imiquimod (Aldara, Zyclara)

Imiquimod 5% cream is used off-label for anal margin lesions. It is applied 3 times per week at bedtime and then washed of in the morning. May apply for maximum of 16 weeks.

Fluorouracil topical (Efudex)

Topical (5-FU) 5% is used off-label for the treatment of AIN of the anal margin. It is applied twice daily for 3-6 weeks.



Class Summary

The 9-valent HPV vaccine is indicated for prevention of HPV-associated neoplasias and precancerous genital lesions. The 2-valent and 4-valent vaccines were discontinued from the US market in 2016.

Children and adolescents aged 15 years and younger need two, not three, doses of the HPV vaccine; this ACIP recommendation stems from the vaccine’s enhanced immunogenicity in preteens and adolescents aged 9-14 years. The schedule for older adolescents and young adults aged 15 through 45 years is three inoculations within 6 months.

Human papillomavirus vaccine, nonavalent (Gardasil 9)

Induces humoral immune response to 9 HPV subtypes: 6, 11, 16, 18, 31, 33, 45, 52, and 58. It is indicated in males and females aged 9 through 45 years to prevent HPV-associated diseases.


PD-1/PD-L1 Inhibitors

Class Summary

Tumor cells may circumvent T-cell–mediated cytotoxicity by expressing PD-L1 on the tumor itself or on tumor-infiltrating immune cells, resulting in the inhibition of immune-mediated killing of tumor cells. PD-1 and PD-L1 inhibitors blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2. This negative feedback loop is essential for maintaining normal immune responses and limits T-cell activity to protect normal cells during chronic inflammation.

Pembrolizumab (Keytruda)

It is indicated for unresectable or metastatic tumor mutational burden-high (TMB-H) [≥10 mut/Mb] solid tumors in patients that have progressed following prior treatment and who have no alternative treatment options.