SPARE-1st: Surgery Alone vs Surgery Plus Postoperative Radiotherapy for Sinonasal Adenoid Cystic Carcinoma

Background:

Sinonasal adenoid cystic carcinoma (ACC) is a rare type of cancer that starts in the nasal cavity or sinuses. Although surgery can remove the tumor, doctors often recommend radiation therapy after surgery to reduce the chance of the cancer coming back. However, radiation can cause long-term side effects such as bone damage, dry mouth, or difficulty opening the mouth. For patients whose tumor has been completely removed (called R0 resection) and who have early-stage disease (T1-T3) without spread to lymph nodes or other organs, it is not clear whether routine radiation therapy is always needed.

Study Objective:

This study aims to find out whether simply watching and waiting (surgery alone) is not worse than adding radiation therapy (surgery plus radiation) in terms of keeping patients free from cancer for at least 3 years. If surgery alone is shown to be as good as surgery plus radiation, some patients may be able to avoid the side effects of radiation.

Study Design:

This is a prospective, multicenter, real-world study. It is not a randomized trial - patients and their doctors will decide together whether to have radiation after surgery. We will follow about 200 patients from many hospitals across China. About half will receive surgery alone, and the other half will receive surgery followed by radiation therapy. All patients will be followed for at least 3 years.

Hypothesis:

We hypothesize that surgery alone is not inferior to surgery plus radiation therapy for 3-year disease-free survival, with a non-inferiority margin of a hazard ratio of 1.35. In other words, even if surgery alone has a slightly higher risk of cancer returning, the difference is small enough that avoiding radiation side effects may still be worthwhile.

Main Outcome:

The main outcome is the percentage of patients who are alive and free from cancer recurrence (local, regional, or distant) or death from any cause at 3 years after treatment.

Potential Impact:

If our hypothesis is confirmed, this study could change current practice. Many patients with completely resected, early-stage sinonasal ACC might safely avoid postoperative radiation and its long-term side effects, improving their quality of life without compromising cancer control.