To what extent is cancer prognosis inherited within families?

Cancer outcomes vary widely between individuals, even among people diagnosed with the same type of cancer. Some patients live much longer or have less aggressive disease than others. This study aims to find out whether these differences in cancer prognosis tend to run in families, which could suggest that inherited factors play a role in how cancer progresses.

We will use TRUST data (a population-based registry) to identify families in which more than one close relative (specifically siblings or parent–child pairs) has been diagnosed with cancer. For each person, we will examine information about their cancer outcome, such as how long they survived after diagnosis, whether the cancer returned, and how advanced the cancer was when it was first detected. By comparing cancer outcomes within families, we will assess whether relatives tend to have similar prognoses more often than would be expected by chance.

Statistical methods will be used to account for important non-genetic factors such as age at diagnosis, sex, and type of cancer. We will also explore whether family similarities differ between cancer types or between cancers diagnosed earlier versus later in life. Understanding whether cancer prognosis clusters within families could improve knowledge about inherited influences on cancer progression and may eventually help identify patients who need closer monitoring or tailored treatment strategies.