Comparing Proton and Photon Therapy for Anal Cancer

Proton Versus Photon Therapy in Anal Squamous Cell Carcinoma - Swedish Anal Carcinoma Study

Not applicable Interventional Umeå University · NCT04462042

This study is testing whether proton therapy causes fewer side effects than photon therapy for people with anal cancer.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorUmeå University Academic / other
Drugs / interventionschemotherapy
Locations4 sites (Gothenburg and 3 other locations)
Trial IDNCT04462042 on ClinicalTrials.gov

What this trial studies

This study aims to compare the side effects of proton beam therapy versus photon therapy in patients with anal squamous cell carcinoma. It is a randomized controlled trial that evaluates the potential of proton therapy to reduce both acute and late side effects associated with treatment. By sparing critical organs at risk, such as bone marrow and intraperitoneal bowel, the study seeks to improve patient comfort and treatment outcomes. Patient-reported and physician-reported data will be collected to assess the effectiveness of these treatment modalities.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with histologically confirmed, previously untreated squamous cell carcinoma of the anal canal.

Not a fit: Patients with cancer of the perianal skin without involvement of the anal canal or those requiring treatments other than radiotherapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to reduced side effects for patients undergoing treatment for anal cancer, improving their quality of life.

How similar studies have performed: While dosimetric studies suggest potential benefits of proton therapy, this is the first randomized trial comparing proton and photon therapies specifically for anal cancer.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. The patient must be at least 18 years old
2. Histologically confirmed, previously untreated squamous cell carcinoma (p16-positive or p16-negative) of the anal canal (ICD-O-3 C21), i.e. cancer of the perianal skin without connection to the anal canal are not included. The patients may have primary tumour, regional nodes, metastasis (TNM)-stage T2 (\>4 cm) -4,N0-1c,M0 (UICC 8th edition).
3. World Health Organisation/Eastern Cooperative Oncology Group (WHO/ECOG) performance status 0-1
4. The patient must be able to understand the information about the treatment and give a written informed consent.

Exclusion Criteria:

1. Patients with cancer of the perianal skin without involvement of the anal canal (ICD-O-3 C44.5) are not eligible.
2. Patient judged to have any other treatment than radiotherapy with concomitant chemotherapy as the preferred treatment
3. Concomitant or previous malignancies. Exceptions are, adequately treated basal cell carcinoma or squamous cell carcinoma of the skin or, other previous malignancy with a disease-free interval of at least 5 years.
4. Two or more synchronous primary cancers in the pelvic region at time of diagnosis
5. Previous radiotherapy, surgery or chemotherapy that may interfere with the planned treatment for the present disease, as judged by the investigator.
6. Co-existing disease prejudicing survival (expected survival should be \>2 years).
7. Pregnancy or breast feeding
8. When prosthetic materials (e.g. hip prostheses) are present close to the target volume it must be considered if this may introduce uncertainties in dose calculations that precludes especially, proton therapy.
9. Patients with pacemaker/ICD are not eligible.

Where this trial is running

Gothenburg and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Anal Cancer Squamous Cellproton beam therapyside effects
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.