The SUMMIT Study will enrol 13,000 participants in order to investigate how cancer screening can be improved and delivered. The SUMMIT Study has two main aims: the first is to clinically validate a blood test for detecting multiple cancers at an early stage. The second is to examine the feasibility of delivering a low-dose CT (LDCT) screening service for lung cancer to a high-risk population in North Central and East London.

The SUMMIT Study is a prospective, observational, cohort study. Its aim is to clinically validate a blood test for the early detection of multiple types of cancer, and to deliver LDCT screening for lung cancer to an at-risk population.

SUMMIT plans to enrol 13,000 participants aged 55-77 years, from participating general practitioner (GP) practices in North Central and East London. The participants enrolled will be people who are at high-risk for lung cancer due to a significant smoking history based on validated risk scores.

Individuals with significant smoking histories will be offered a clinical Lung Health Check (LHC), which includes a brief respiratory consultation including questions about respiratory symptoms and medical history, smoking cessation advice and referral where required, and certain relevant clinical measurements (blood pressure, spirometry, height, and weight). Those persons who are eligible for participation based on specific validated risk scores may then be offered participation in the SUMMIT Study. Electronic informed consent will be obtained if they decide to take part. Consented participants will provide a blood sample, complete a confidential electronic questionnaire and have an LDCT scan at the same visit. Participants will be asked to return for two further annual visits, and some participants may return for additional scans if clinically indicated (nodule management).

If any LDCT result is suspicious for cancer, the participant will be referred to their local hospital (type 2 Site) via an urgent referral pathway to the relevant MDT. If a participant is diagnosed with lung cancer, that participant will no longer continue in the active/interventional part of the study but will be followed for clinical outcomes via the Type 2 site completion of eCRF and registry data. If the suspicious lesion is found to be benign, the participant can continue in the study.

There will be one randomisation round carried out during this study. All participants with a negative LDCT at the baseline visit who have not been diagnosed with lung cancer since that visit will return for an LHC at approximately 12 months. At the 12-month visit, this group will be randomised either to have an LDCT or no LDCT.

However, if an urgent referral was after the Y0 LDCT scan, the participant will not be included in the randomisation at Y1, and will receive LDCT at Y1 and Y2.

Inclusion Criteria:

1. Individuals 55 to 77 years old at the time of GP data extraction, who meet either of the following criteria:

   1. USPSTF LDCT screening criteria: a history of at least 30 pack years of smoking and if a former smoker, have quit in the past 15 years; or
   2. PLCOm2012 6-year lung cancer risk of ≥1.3%

2. Capable of providing informed consent and willing to comply with all parts of the protocol

Exclusion Criteria:

Currently receiving treatment (e.g., chemotherapy, radiotherapy, watchful waiting) for an active cancer. If on adjuvant hormonal therapy can be included (e.g. for breast and prostate cancer).

SUMMIT plans to enrol 13,000 participants, aged 55-77 years, from participating GP practices in north and east London who are at high-risk for lung cancer due to a significant smoking history.