SOLO Pilot Study: Testing New Anal Cancer Screening Swabs

January 26, 2026 updated by: Alan Nyitray, PhD, Medical College of Wisconsin

The Self-Sampling to Optimize Anal Lesion Outcomes (SOLO) Pilot study is an important research project focused on improving anal cancer screening methods. This study compares two different insertion depths (3 cm vs. 5 cm) for a new type of nylon-flocked swab used in self-collection of anal cell samples.

Anal cancer screening is particularly important for certain high-risk populations, including sexual minority men and transgender women. The researchers are testing whether inserting the swab deeper (5 cm) collects better samples from the squamocolumnar junction (SCJ) - the area where anal cancer most often develops - compared to the more standard 3 cm insertion depth.

The study will enroll 60 participants aged 35 or older from the Milwaukee area who previously participated in related research and expressed interest in follow-up studies. Participants will be randomly assigned to use either the 3 cm or 5 cm insertion method during a private self-sampling procedure at the Medical College of Wisconsin.

After collecting the sample, researchers will examine:

  1. Whether deeper insertion collects more cells from the important SCJ area
  2. If the samples are adequate for laboratory testing
  3. How comfortable each method is for participants

This research is crucial because:

  • Anal cancer rates are rising, especially in high-risk groups
  • Current screening methods can be uncomfortable, leading to low participation
  • Self-sampling could make screening more accessible and private
  • The original swab used in previous studies is no longer available

Participants will receive their individual test results, though researchers note these shouldn't be used alone for medical decisions since anal self-sampling isn't yet FDA-approved for clinical use. The study takes about one month to complete, with all activities happening during a single visit.

This pilot study will help determine if the new swab performs as well as previous versions and whether deeper insertion improves sample quality without causing too much discomfort. The findings will guide the larger SOLO parent study and potentially influence future anal cancer screening programs.

Anal cancer prevention research is particularly vital as incidence rates continue to climb, especially among HIV-positive individuals and sexual minority populations. Early detection through effective screening methods could significantly reduce mortality rates. This study represents an important step toward developing more accessible and patient-friendly screening options that could ultimately save lives through earlier detection of precancerous changes.

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