What is the recommended treatment approach for tumors in HIV (Human Immunodeficiency Virus) patients?

Treatment Approach for Tumors in HIV Patients

HIV-infected patients with tumors should receive standard cancer therapy appropriate for their tumor type while maintaining antiretroviral therapy (ART), with treatment decisions guided by a multidisciplinary team including an oncologist and HIV specialist. 1

General Management Principles

HIV Management During Cancer Treatment

• HIV screening: All patients with cancer should be screened for HIV 1
• Antiretroviral therapy:
  • ART should be initiated or continued during cancer treatment 1
  • ART interruptions should be avoided due to risk of immunologic compromise, opportunistic infections, and death 1
  • Continuation of ART improves tolerance of cancer treatment, response rates, and survival 1
  • Pretreatment plasma viral load should be checked and cancer therapy should be administered when viral load is undetectable 1

Collaborative Care

• All HIV patients with cancer should be co-managed by an oncologist and HIV specialist 1
• Consultation with HIV pharmacist and oncology pharmacist is recommended to manage drug interactions 1
• Cancer treatment should not be delayed for HIV workup when possible 1

Specific Considerations for Cancer Treatment

Immunotherapy Considerations

• HIV-infected individuals with tumor types that are candidates for immunotherapy should be considered for cancer treatment 1
• For anti-PD-1/PD-L1 therapy:
  • Pretreatment CD4+ T cell counts should preferably be above 200 cells/mm³ 1
  • Patients with CD4+ T cell counts below 100 cells/mm³ require careful risk-benefit assessment 1
  • Pembrolizumab is the preferred anti-PD-1 antibody based on prospective and retrospective data 1

Chemotherapy Considerations

• Standard chemotherapy regimens should be used but may require modifications:
  • Consider dose reduction in early cycles if CD4+ T cell count is <100 cells/μL 1
  • Growth factor support is strongly recommended for all regimens in HIV patients 1
  • For AIDS-related Kaposi's sarcoma, paclitaxel 135 mg/m² IV over 3 hours every 3 weeks or 100 mg/m² IV over 3 hours every 2 weeks is recommended 2
  • For HIV patients receiving paclitaxel:
    • Reduce dexamethasone premedication to 10 mg PO (instead of 20 mg) 2
    • Only initiate treatment if neutrophil count is ≥1,000 cells/mm³ 2
    • Reduce subsequent doses by 20% for severe neutropenia 2
    • Consider concomitant G-CSF as clinically indicated 2

Infection Prophylaxis

Required/Strongly Recommended Prophylaxis

• Pneumocystis jirovecii pneumonia (PJP) prophylaxis:

  • Continue until CD4+ T cell counts recover to ≥200 cells/μL for ≥3 months after completion of cancer therapy 1
  • Example: Sulfamethoxazole-trimethoprim 800 mg/160 mg (double-strength) one tablet PO three times weekly 1

• Herpes simplex virus/Varicella zoster virus prophylaxis:

  • Continue until completion of cancer therapy 1
  • Example: Acyclovir 400-800 mg PO twice daily OR valacyclovir 500 mg PO twice daily 1

• Gram-negative infection prophylaxis:

  • Quinolone prophylaxis during periods of neutropenia 1
  • Example: Ciprofloxacin 500-750 mg PO every 12 hours OR levofloxacin 500-750 mg PO daily 1

• Mycobacterium avium complex (MAC) prophylaxis:

  • Continue until CD4+ T cell counts recover to ≥100 cells/μL for ≥3 months after completion of cancer therapy 1
  • Example: Azithromycin 1200 mg PO once weekly 1

Additional Prophylaxis to Consider

• Antifungal prophylaxis during periods of prolonged neutropenia (≥7 days) 1
  • Fluconazole 400 mg PO daily OR posaconazole 300 mg PO twice daily on day 1 followed by 300 mg PO daily 1
  • Note: Azole antifungals may interact with ART and chemotherapy; should typically be held 24 hours before through 24 hours after administration of cancer therapy metabolized via CYP3A4 1

Monitoring During Treatment

• More frequent HIV viral load testing (e.g., monthly for first 3 months, then every 3 months) 1
• Consider measuring CD4+ T cell count more frequently in patients receiving cancer treatments anticipated to cause lymphopenia 1
• Monitor for drug interactions between ART and cancer therapy 1
• High index of suspicion for opportunistic infections, including early testing for fungal and cytomegalovirus infections 1

Special Considerations

Antiretroviral Drug Interactions

• Avoid if possible:
  • Ritonavir, cobicistat, and protease inhibitors due to common adverse drug interactions 1
  • Non-nucleoside reverse transcriptase inhibitors may result in decreased efficacy 1
  • Zidovudine due to myelosuppression 1
  • Didanosine and stavudine due to additive peripheral neuropathy 1

Imaging Interpretation

• Interpretation of diagnostic and staging imaging may be complicated by increased incidence of non-malignant lesions 1
• PET/CT-guided therapy is feasible but care should be taken to recognize potential confounding factors (non-malignant causes for PET-avid regions) 1
• MRI is the optimal method for staging CNS lymphomas, but cerebral opportunistic infections may mimic lymphoma in HIV patients 1

Common Pitfalls to Avoid

1. Delaying cancer treatment unnecessarily - Cancer treatment should not be delayed for HIV workup when possible 1
2. Interrupting ART during cancer treatment - This increases risk of opportunistic infections and death 1
3. Failing to provide adequate prophylaxis - HIV patients receiving cancer therapy need comprehensive infection prophylaxis 1
4. Overlooking drug interactions - Always check for interactions between cancer therapy and ART 1
5. Misinterpreting imaging findings - Non-malignant lesions may be mistaken for cancer spread or recurrence 1
6. Underutilizing growth factors - Myeloid growth factor support should be strongly considered even for regimens with low risk of febrile neutropenia 1