A scientist is researching the long term effects of the hepatitis viruses on hepatic tissue. She finds that certain strains are oncogenic and increase the risk of hepatocellular carcinoma. However, they appear to do so via different mechanisms. Which of the following answer choices correctly pairs the hepatitis virus with the correct oncogenic process?

Hepatitis B virus - integration of viral DNA into host hepatocyte genome

Hepatitis A virus - chronic inflammation

Hepatitis C virus - chronic inflammation

Hepatitis E virus - integration of viral DNA into host hepatocyte genome

Hepatitis A virus - integration of viral DNA into host hepatocyte genome

A 31-year-old female presents to her gynecologist for a routine Pap smear. Her last Pap smear was three years ago and was normal. On the current Pap smear, she is found to have atypical squamous cells of unknown significance (ASCUS). Reflex HPV testing is positive. What is the best next step?

Repeat Pap smear and HPV testing in 5 years

Loop electrosurgical excision procedure (LEEP)

A 27-year-old woman comes to the physician for a routine health maintenance examination. She feels well. She had a chlamydia infection at the age of 22 years that was treated. Her only medication is an oral contraceptive. She has smoked one pack of cigarettes daily for 6 years. She has recently been sexually active with 3 male partners and uses condoms inconsistently. Her last Pap test was 4 years ago and results were normal. Physical examination shows no abnormalities. A Pap test shows atypical squamous cells of undetermined significance. Which of the following is the most appropriate next step in management?

Perform loop electrosurgical excision procedure

A 17-year-old high school student presents to the physician’s office for a health maintenance examination. He is a recent immigrant from Venezuela and has no complaints at this time. Past medical history is significant for appendicitis at age 10, treated with an appendectomy. He denies the use of alcohol and cigarettes. He admits to occasionally smoking marijuana with his friends. He is sexually active with 1 woman partner and uses condoms inconsistently. The vital signs are within normal limits. Physical examination is unremarkable except for a laparoscopic surgical scar on the right iliac region. Routine blood tests are pending. What is the most appropriate next step in management?

HPV vaccine as a legal adult at age 18

Ceftriaxone and azithromycin as prophylaxis

Azithromycin as prophylaxis only

A 16-year-old girl comes to her primary care physician for an annual check-up. She has no specific complaints. Her medical history is significant for asthma. She uses an albuterol inhaler as needed. She has no notable surgical history. Her mom had breast cancer and her grandfather died of colon cancer. She received all her childhood scheduled vaccinations up to age 8. She reports that she is doing well in school but hates math. She is sexually active with her boyfriend. They use condoms consistently, and they both tested negative recently for gonorrhea, chlamydia, syphilis and human immunodeficiency virus. She asks about birth control. In addition to educating the patient on her options for contraception, which of the following is the best next step in management?

No HPV-related screening and administer HPV vaccine

Cytology and human papilloma virus (HPV) testing now and then every 3 years

No HPV-related screening as the patient is low risk

Cytology and HPV testing now and then every 5 years

Cytology now and then every 3 years

A 30-year-old woman presents to the clinic because of fever, joint pain, and a rash on her lower extremities. She admits to intravenous drug use. Physical examination reveals palpable petechiae and purpura on her lower extremities. Laboratory results reveal a negative antinuclear antibody, positive rheumatoid factor, and positive serum cryoglobulins. Which of the following underlying conditions in this patient is responsible for these findings?

Systemic lupus erythematosus (SLE)

Cancer prevention strategies for oncogenic viruses for USMLE Step 1: High-Yield Microbiology Lessons

Prevention Pillars - Rogues' Gallery

Primary Prevention (Vaccination): Pre-empts infection.
- HPV (Gardasil 9)
- HBV
Secondary Prevention (Screening): Catches early changes.
- Pap smear (HPV)
- HCV antibody tests
Risk Reduction & Treatment: Limits exposure & viral effects.
- Safe sex (HHV-8, HIV)
- Blood product screening (HCV, HTLV-1)
- Antivirals (HBV, HCV, HIV)

⭐ The HPV vaccine prevents over 90% of cervical cancers. It is ideally administered at ages 11-12, but approved for individuals up to age 45.

Vaccination - Prophylactic Power-ups

Primary Prevention: Vaccines are a cornerstone strategy to prevent cancers caused by viruses, targeting them before they can establish chronic infection.
Hepatitis B (HBV) Vaccine:
- Mechanism: Recombinant vaccine containing Hepatitis B surface antigen (HBsAg).
- Prevents: Hepatocellular carcinoma (HCC) by preventing chronic HBV infection.
- Schedule: Routinely administered to all infants in a 3-dose series starting at birth.
Human Papillomavirus (HPV) Vaccine:
- Mechanism: Composed of L1 capsid proteins that self-assemble into non-infectious virus-like particles (VLPs).
- Spectrum: Gardasil 9 targets 9 types (high-risk 16, 18, 31, 33, 45, 52, 58; low-risk 6, 11).
- Prevents: Cancers of the cervix, anus, oropharynx, penis, vulva, and vagina.
- Schedule: Recommended for ages 11-12; can be given up to age 45 based on shared clinical decision-making.

HPV VLP mechanism of action for antibody induction

⭐ High-Yield Pearl: HPV vaccines are prophylactic, not therapeutic. They are highly effective at preventing new infections but do not clear existing HPV infections or treat HPV-associated lesions.

Screening & Treatment - Damage Control

Human Papillomavirus (HPV):
- Screening: Pap test (cervical cytology) & HPV DNA testing.
- Protocols: Begin at age 21. Pap test every 3 years, or HPV co-testing every 5 years for ages 30-65.
- Management: Abnormal results trigger colposcopy with biopsy. High-grade cervical intraepithelial neoplasia (CIN) is treated with Loop Electrosurgical Excision Procedure (LEEP) or ablation to prevent progression to invasive carcinoma.
Hepatitis B (HBV) & C (HCV):
- HCC Surveillance: In patients with chronic infection or cirrhosis, screen with liver ultrasound ± alpha-fetoprotein (AFP) every 6 months.
- Treatment: Antiviral therapy (e.g., Tenofovir for HBV, DAAs for HCV) suppresses viral replication, reduces hepatic inflammation, and significantly lowers the risk of developing hepatocellular carcinoma.
EBV & HHV-8:
- No routine screening protocols exist. Diagnosis relies on clinical presentation and tissue biopsy of suspected malignancies (e.g., Kaposi sarcoma, nasopharyngeal carcinoma).

⭐ Treatment of Hepatitis C with Direct-Acting Antivirals (DAAs) achieves a sustained virologic response (cure) in >95% of patients, dramatically reducing the long-term risk of hepatocellular carcinoma.

Cervical Changes: Normal to Cancer Progression

High‑Yield Points - ⚡ Biggest Takeaways

HPV vaccination (Gardasil, Cervarix) is the primary prevention for cervical, anogenital, and oropharyngeal cancers.

HBV vaccination is highly effective in preventing hepatocellular carcinoma (HCC).

Treating chronic HCV with direct-acting antivirals (DAAs) cures the infection and dramatically reduces HCC risk.

Cervical cancer screening using Pap smears and HPV testing is critical for secondary prevention.

Managing immunosuppression is key to preventing EBV and HHV-8 associated malignancies.

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