Mapping your family cancer history

Many families have a pretty good idea of who in the immediate family, if anyone, has been affected by what cancer type, and sometimes even as far out as aunts, uncles, and cousins. But as soon as you look back one more generation it becomes a little less clear. You may, for example, know that grandpa passed away from cancer but not be sure which type he had. Or that grandma passed away at a young age, and that they say it was probably cancer.

Because of this we sometimes get questions about how you can map out your family’s cancer history. In this blog post we’re going to explain just that. Please keep in mind that this information will not be relevant for those with family members that were diagnosed with cancer in a country other than Sweden.

Personal numbers are key

As part of a hereditary assessment via the Swedish healthcare system you’ll receive help mapping your family’s cancer history, which is one reason why such an assessment may take a long time to complete. In order to confirm the cancer diagnosis of a relative you will need to have their Swedish personal number (“personnummer”). This can be obtained a variety of ways. One great resource is Sweden’s death book which contains records of those deceased in Sweden from 1860 to 2017. The records include name, birth and death dates, marital status, address, and often even personal number. In order to obtain a personal number, however, it is required that you provide certain information about your passed relative in order to get a unique hit in the registry.

Another method of obtaining a relative’s personal number is by contacting Sweden’s tax agency (Skatteverket) which took over civil registration from the Swedish Church in 1991. If an individual who was born in the early 1900’s was still alive in 1991, it is highly likely that their records are stored at Skatteverket. As long as Skatteverket has the record, then you can request it.

How to confirm a relative’s cancer diagnosis

Once you have obtained a personal number you are well on your way. The healthcare system uses Sweden’s cancer register to look up a cancer diagnoses as far back as 1958. The register contains information such as personal number, sex, hometown at diagnosis, reporting hospital and clinic, date of diagnosis, clinical and morphological diagnosis, and tumor invasiveness at time of diagnosis. A power of attorney from the nearest living relative of the deceased person is required in order to export information from the cancer register.

Private individuals are not able to export from the cancer register. What they can do is request medical records from a region’s or hospital’s archives. Just as with the cancer register, a power of attorney from the nearest living relative is required for such a request. A certificate of kinship or other proof that the individual truly is the nearest living relative may be required.

The archives are protected by secrecy for 70 years, but records may be disclosed if it determined that no one individual suffers harm. In other words, a special assessment of whether or not a record can be disclosed is required for relatives who were diagnosed with cancer after 1951 (as of the writing of this article in 2021). In addition to your relative’s personal number, you will also need to know the hospital and clinic at which they were treated for their cancer. You must also specify which pieces of information you would like disclosed. The PD (PAD-svar in Swedish), or pathological diagnosis, often provides sufficient information regarding cancer type. The medical records are another alternative.

The importance of family history

Your family’s cancer history plays an important role in determining which genes to analyze. This is less relevant should you choose a comprehensive panel such as GeneMate® 41 genes, but very relevant in the case of selecting a targeted panel such as GeneMate® Colon. The healthcare system exclusively uses targeted panels, which in turn makes family cancer history extremely important in the decision-making process.

Family cancer history is also important in determining which screening program is appropriate for an individual without a pathogenic gene mutation. For example, an individual with three close relatives which pancreatic cancer, one of which is a first-degree relative (such as a father) and the other two are first-degree relatives to each other (such as father’s father and sister), should be offered a screening program for pancreatic cancer solely based on their family cancer history. For that reason, there may be value in confirming that grandpa’s cancer truly was pancreatic cancer.