Efficacy of Combination Treatment for Cervical Precancer Among Women Living with HIV in South Africa: Secondary Outcomes from the ACT 2 Randomized Controlled Trial

Secondary outcomes from the ACT 2 randomized controlled trial indicate that adjuvant intravaginal 5-fluorouracil cream following LEEP significantly improves histologic regression of cervical precancer in women living with HIV, particularly among those with positive LEEP margins, although it did not significantly enhance high-risk HPV clearance compared to placebo.

The Gist

The Big Picture: A "Double-Whammy" Strategy for Cervical Cancer Prevention

Imagine the cervix (the entrance to the uterus) as a garden. Sometimes, weeds (precancerous cells called CIN 2/3) start growing there. If you don't pull them out, they can turn into a massive, destructive forest fire (cervical cancer).

For women living with HIV, this garden is much more vulnerable. Their immune systems, which usually act like the garden's security guards, are a bit tired. Because of this, when they get weeds, the weeds grow back faster and more stubbornly than in other women.

The Study's Goal:
Researchers in South Africa wanted to test a new "two-step" strategy to clear these weeds for women with HIV. They asked: If we cut the weeds out, but then also spray a special "weed killer" on the soil, will the garden stay clean longer?

The Experiment: The "Cut and Spray" Trial

The researchers ran a test called the ACT 2 trial. Here is how they did it:

1. The Participants: They recruited 180 women living with HIV in South Africa who had already been diagnosed with these precancerous weeds.
2. The First Step (The Cut): Everyone got a standard surgery called LEEP. Think of this as using a hot wire loop to slice out the visible weeds and the soil they are rooted in. This is the standard treatment.
3. The Second Step (The Spray): After the surgery, the women were randomly split into two groups:
   • Group A (The Real Deal): They used a cream containing 5-Fluorouracil (5FU). This is a common, cheap chemotherapy drug that acts like a potent weed killer. They applied it vaginally (like a suppository) twice a week for a few months.
   • Group B (The Placebo): They used a cream that looked and felt exactly the same but had no medicine in it. This was the control group to see if the act of applying cream helped, or if it was the medicine doing the work.

The "Blind" Rule: Neither the women nor the doctors knew who got the real cream and who got the fake one until the study was over. This ensures the results are fair.

The Results: Did the Weed Killer Work?

After six months (24 weeks), the researchers checked the gardens again. Here is what they found:

• The "Clean Garden" Rate:

  • In the 5FU Group (Real Weed Killer), 96% of the women had their gardens completely cleared of dangerous weeds. They were either back to normal or had only very minor, harmless patches left.
  • In the Placebo Group (Fake Cream), only 82% had cleared gardens.
  • The Takeaway: The women using the real medicine were significantly more likely to stay weed-free.

• The "Stubborn Weeds" Scenario:

  • Sometimes, during surgery, the doctor can't be 100% sure they got every single root (called "positive margins"). This is like cutting a weed but leaving a tiny root hidden underground.
  • In this difficult scenario, the 5FU group was much better at cleaning up the mess. 88% of them cleared the weeds, compared to only 61% in the placebo group.
  • The Metaphor: The spray was like a "mop-up crew" that went in after the main cutters left to kill the hidden roots that the surgery missed.

• The Virus (HPV):

  • The study also checked if the Human Papillomavirus (the seed that causes the weeds) was gone. Interestingly, the spray didn't clear the virus significantly faster than the placebo.
  • The Insight: This suggests the cream isn't necessarily killing the virus itself, but rather killing the cells that the virus has already infected. It's like the spray kills the infected plants, preventing them from spreading, even if the "seed" (virus) is still technically present in the soil.

Why This Matters

1. It's a "Game Changer" for Low-Cost Medicine: The drug used (5FU) is a generic, very cheap, and widely available medicine. It doesn't require fancy machines or expensive labs.
2. It's Self-Administered: The women applied the cream themselves at home. This is huge for places where it's hard to get to a hospital for frequent check-ups.
3. Safety: The study confirmed that this "double-whammy" approach is safe and that women were willing to use it.

The Bottom Line

Think of this study as proving that cutting out the weeds isn't always enough for a vulnerable garden. You need a follow-up treatment to make sure they don't grow back.

For women living with HIV in South Africa (and potentially other places with similar challenges), adding a cheap, self-applied cream after surgery could be the difference between a garden that stays clean and one that gets overrun by cancer. While more large-scale studies are needed to confirm this, the results are very promising and offer a hopeful, affordable new tool in the fight against cervical cancer.

Technical Summary

1. Problem Statement

Women living with HIV (WLWH) face a significantly elevated risk of cervical cancer compared to the general population. In sub-Saharan Africa, where the burden of HIV is high, standard surgical treatments for cervical intraepithelial neoplasia grade 2/3 (CIN2/3), such as Loop Electrosurgical Excision Procedure (LEEP), are associated with high recurrence rates (20–55%), compared to 5–10% in HIV-negative women. There is an urgent need for novel, low-cost, and accessible adjuvant therapies to improve treatment outcomes and reduce recurrence in this vulnerable population, particularly in low- and middle-income countries (LMICs).

2. Methodology

• Study Design: A double-blind, Phase 2b, randomized, placebo-controlled feasibility trial (ACT 2).
• Setting: South Africa (Clinical HIV Research Unit, Johannesburg).
• Population: 180 WLWH with confirmed CIN2/3 via LEEP histology.
  • Inclusion Criteria: Virologically suppressed (99% had HIV RNA <200 copies/mL), median CD4 count >600 cells/µL.
  • Exclusion: CIN1 only or invasive cancer.
• Intervention:
  • Experimental Arm: LEEP followed by self-applied intravaginal 5% 5-fluorouracil (5FU) cream (8 doses, biweekly).
  • Control Arm: LEEP followed by placebo cream (8 doses, biweekly).
• Primary Outcomes (Feasibility): Acceptability, safety, and adherence (reported in a separate publication).
• Secondary Outcomes (This Paper):
  1. Histologic Regression: Proportion of participants regressing to CIN1 or normal histology at 24 weeks.
  2. HPV Clearance: Genotype-specific clearance of high-risk HPV (hrHPV) at 24 weeks.
• Data Collection & Analysis:
  • Follow-up at 24 weeks included colposcopically directed biopsies and hrHPV testing via GeneXpert (Cepheid).
  • Histology reviewed by blinded pathologists using p16 immunohistochemistry.
  • Statistical analysis used an Intention-to-Treat (ITT) approach with Wilson Score and exact Clopper-Pearson confidence intervals.

3. Key Contributions

• First RCT in Africa: This is the first randomized controlled trial evaluating a topical therapy for CIN2/3 in an African setting.
• Adjuvant Strategy: It validates the use of a low-cost, generic, self-applied topical agent (5FU) as an adjuvant to standard surgical excision.
• High-Quality Data: The study utilized blinded pathology review with p16 staining (rare in LMIC studies) and rigorous virologic monitoring in a cohort of well-controlled HIV patients.
• Targeted Subgroup Analysis: It specifically addresses the efficacy of adjuvant therapy in cases with positive surgical margins, a critical clinical scenario where recurrence risk is highest.

4. Key Results

Demographics and Baseline:

• Median age: 41 years.
• 99% of participants were virologically suppressed; median CD4 count was 636 cells/µL.
• Baseline hrHPV detection: 87.1% (HPV16: 29%, HPV18/45: 18%).

Histologic Regression (Week 24):

• Overall: The 5FU group showed significantly higher regression to CIN1 or normal compared to placebo.
  • 5FU Group: 96.3% (78/81) regressed.
  • Placebo Group: 82.0% (73/89) regressed.
  • Difference: 14.3% (95% CI: 5.3%, 23.3%).
• By Lesion Severity:
  • CIN2: 96.7% (5FU) vs. 85.7% (Placebo).
  • CIN3: 96.1% (5FU) vs. 79.6% (Placebo).
• Positive Surgical Margins (Exploratory):
  • Among participants with positive margins, 5FU demonstrated a substantial benefit: 88.0% (22/25) regressed vs. 61.3% (19/31) in placebo (Difference: 26.7%, 95% CI: 5.4%, 48.1%).
• Progression: No participants progressed to invasive cancer during the 24-week follow-up.

HPV Clearance (Week 24):

• Genotype-Specific Clearance: No statistically significant difference was observed between groups.
  • 5FU: 58.0% clearance.
  • Placebo: 53.8% clearance.
  • Difference: 4.2% (95% CI: -11.7%, 20.2%).
• Observation: HPV clearance appeared to occur primarily in the first 4 weeks (post-LEEP, pre-treatment), suggesting the benefit of 5FU may be driven by the clearance of residual microscopic disease rather than new viral clearance.

Risk Reduction Metrics:

• Relative Risk Reduction: 79% reduction in persistent CIN2/3 for the 5FU group (Probability Ratio: 0.21).
• Number Needed to Treat (NNT): 7 (95% CI: 4, 24). Treating 7 women with adjuvant 5FU results in one additional case of regression to CIN1/normal.

5. Significance and Conclusion

The ACT 2 trial demonstrates that adjuvant intravaginal 5FU following LEEP is a beneficial treatment strategy for WLWH with CIN2/3, particularly in reducing persistent disease and managing cases with positive surgical margins.

• Clinical Impact: The intervention offers a potential solution to the high recurrence rates seen in WLWH. With an NNT of 7, it represents a highly efficient intervention.
• Feasibility in LMICs: 5FU is a generic, low-cost, and widely available drug. The self-application model is feasible and acceptable, as confirmed by the study's primary feasibility outcomes.
• Future Directions: While the Phase 2b results are promising, the authors note the study was not fully powered for definitive efficacy conclusions. They recommend a larger Phase 3 trial to confirm these findings and further investigate the mechanism of action regarding viral clearance versus histologic regression.

In summary, this study provides strong evidence for integrating topical 5FU into cervical cancer prevention protocols for women living with HIV in resource-limited settings.