"A lot can happen in that time": understanding patients' perspectives on reduced surveillance frequency and the potential for circulating tumor DNA blood tests after colorectal cancer treatment.

PURPOSE: Individuals who have completed colorectal cancer (CRC) treatment are recommended regular radiological scans for 3-5 years to monitor for cancer recurrence. Since the frequency of radiological surveillance is generally reduced until it is no longer recommended, blood tests measuring circulating tumor DNA (ctDNA) could supplement and/or replace radiological surveillance once scans are not recommended. To better understand patients' support needs throughout ongoing care after CRC treatment, this study explored perspectives on reduced scan frequency and the potential incorporation of ctDNA tests.

METHODS: Eight focus groups were conducted with 21 individuals (11 males; median age at diagnosis 61 years) who received CRC treatment in South Australia. Reflexive thematic analysis was used to develop and interpret themes.

RESULTS: Participants' reported mental wellbeing was linked to their perceived health status following CRC treatment, and radiological surveillance was important in forming these perceptions. Perspectives on reduced surveillance frequency differed by participants' level of health anxiety. Although some individuals interpreted surveillance changes as a positive indicator of their ongoing cancer-free health, others felt this would lead to more uncertainty regarding their cancer status. Participants supported the incorporation of ctDNA blood tests to provide additional information about their risk of recurrence.

CONCLUSION: Individuals lacking information about their cancer status may have a higher risk of experiencing adverse mental health outcomes (e.g., fear of cancer recurrence) following reductions in surveillance frequency. Using ctDNA tests may help decrease fears of recurrence and support perceptions of good health during times of radiological surveillance change.