A Single Arm Feasibility Study of Exercise for Improving Short-course Radiotherapy Efficacy in People Diagnosed With Locally Advanced Rectal Cancer

This study will take place at Castle Hill Hospital, where the participants' usual care will be given. The study will also recruit at this site. Patients, who have been diagnosed with locally advanced rectal cancer (LARC) short-course radiotherapy (NART) will be pre-screened for any obvious exclusions with those that are potentially eligible approached by their clinical oncologist to discuss participation in these studies. If the patient is agreeable, further contact will be made by a member of the research team for further discussion. The aim is to include about 30 participants in this study. The participant information sheet will be provided and any uncertainties about the study raised by the potential participant will be addressed. The potential participant will be given sufficient time, up to a week, to consider their participation in the study, as typically, there is on average a 31-day period between decision to treat and start of neoadjuvant oncological treatment. After all questions are answered and provided the participant is willing to take part in the study, they will be asked to sign the consent form to confirm participation.

Once a participant agrees to taking part, their medical history, and investigations (performed as part of routine clinical care) will be reviewed. Each participant's data from investigational phase for rectal cancer up to short-course NART completion and re-assessment will be collected. Data on age, gender, stage of rectal cancer, and any comorbidities will be collected from medical notes. Participants will then be invited for a baseline assessment at Castle Hill Hospital in a designated risk assessed rehabilitation gym.

In this baseline assessment, further personal details will be taken from the patient, including height and weight measurements to calculate Body Mass Index (BMI), other descriptive information such as ethnicity will also be taken. The Patient Reported Outcome Measures (PROMs) will be completed either independently by participant or with the help of a member of the research team if required by participant. Some of the questionnaires, such as the European Organisation for Research and Treatment of Cancer EORTC-QLQ-CR29 and Functional Assessment of Cancer Therapy - Colorectal (FACT-C), contained in this study contain some questions that may be perceived to be intrusive. They however are validated questionnaires that has previously been used in numerous rectal cancer research studies. To mitigate embarrassment, participants will be forewarned about the contents of these questionnaires and potential to cause embarrassment. Participants will be reminded that their response will be anonymised. Questions relating to stoma and sex life are presented much later in the questionnaires where rapport may have already been established. Participants will be encouraged to consult with their oncologist if the questionnaires prompt any treatment related problems they may be experiencing.

Participants will also on this day, be provided an accelerometer to wear on 7 randomly selected days at different timeframes of the study. Finally on this day an average of three resting heart rates will be taken. The value of the average of the resting hear rates will be used in calculating a heart rate reserve (HRR) of 60%, 70% and 80%. Using the formula (HRmax-RHR) × exercise intensity (60-80%) + RHR, where HRmax is 220-Age as found to be effective. This will form one of the main bases for exercise intensity, to ensure individualisation of the supervised vigorous intensity interval training sessions.

The supervised hospital-based exercise will be delivered over a 7-week period. This is because short-course neoadjuvant radiotherapy lasts 5-days in a week. This design allows for a 2-week pre-neoadjuvant oncological and a 4-week post-neoadjuvant oncological treatment. Exercise will involve an hour long, twice weekly vigorous intensity aerobic interval exercise and twice weekly supported at-home resistance training, from 2 weeks prior to the start of oncological treatment to the beginning of NART. In the week of NART, participants will receive 5 consecutive days of vigorous intensity aerobic interval training 1.5 hours before radiotherapy only. Following this week of short-course NART, participants will return to receiving twice weekly vigorous intensity aerobic interval exercise and twice weekly supported at-home resistance training, for four weeks. Vigorous intensity aerobic interval exercise will be performed at 70-80% of heart rate reserve (HRR).