Second Primary Cancer Screening: Role of the Primary Care Physician

The number of cancer survivors is rapidly increasing owing to early detection of cancer and improvement in the rate of cancer treatment. According to statistics provided by the Korea Central Cancer Registry, in 2014, there were more than 1.4 million cancer survivors in Korea, which is 1 per 35 people of the total population. Therefore, interest in the health problems of cancer survivors is increasing recently.1)

Second primary cancers (SPCs) refer to newly developed primary cancers in people with a history of cancer. In population-based studies, the risk of SPC is approximately 1.1–1.6 times that of the general population.2) In countries with high cancer survival rates, SPCs account for a large proportion of the overall cancer incidence—16% in the United States and 8.5% in Sweden.34) In the case of cancer patients who have good prognosis, secondary cancer, and not primary cancer, is the likely cause of death; for example, in breast cancer survivors, SPC increases the risk of death by approximately 3–4 times.5)

In the present issue, Lee et al.6) report an investigation of breast and cervical cancer screening rates in female cancer survivors in Korea compared to those without cancer, using data from the 2007–2012 Korean National Health and Nutrition Examination Survey (KNHANES).6) In this study, the screening rate for breast cancer in cancer survivors was higher than that in the non-cancer control group (56.6% versus 44.9%). However, the screening rate for cervical cancer in cancer survivors was similar to that in the non-cancer control group (51.4% versus 49.3%).

The National Cancer Screening Program of Korea set a goal of achieving a screening rate of 70% by 2015. Cancer survivors have a higher incidence of SPC than does the general population; therefore, cancer screening rate should be at least as high as that recommended for the general population. However, the SPC screening rates reported in Lee et al.6)'s study and other previous studies are low. In the studies using the 2001, 2005, and 2007 KNHANES database, screening rates in cancer survivors were reported to be 48.5% and 54.7% for breast and cervical cancer, respectively.7) In a subsequent study in 2011 by Shin et al.,8) which examined oncology care in outpatient clinics, the screening rates for breast cancer and cervical cancer were reported to be 62.4% and 65.5%, respectively. In this study, the rate of screening for four cancers, including gastric cancer and colorectal cancer, was only 37.5%.

The reasons for low cancer screening rate in cancer survivors are the lack of knowledge in cancer survivors about SPC and SPC screening, and the lack of recommendation from medical staff for SPC screening. A possible solution to this low secondary cancer screening rate would be a “shared care model” in which the primary care physician communicates with the oncologist and actively participates in the treatment of cancer patients and family members.9) In this model, the primary care physician and oncologist play a complementary role by sharing the care of the patient post cancer diagnosis. In this model, while the oncologist intervenes more during the primary cancer treatment, the primary care physician intervenes later on as per the treatment regime. Oncologists tend to not consider SPC screening a part of their job. It has been also observed that cancer survivors followed-up by both primary care providers and oncologists were more likely to be subjected to SPC screening and other comprehensive care than those followed-up by oncologists only.10) This is due to comprehensiveness, which is a key element of primary care. Comprehensiveness is the concept on which the primary care clinician recognizes and meets majority of the patient's physical and common mental healthcare needs, including disease prevention.

Apart from comprehensiveness, the continuity of care is also a core element of primary care. These characteristics can play a vital role in proper execution of long-term medical care such as SPC screening. The rate of SPC screening usually declines with time since the primary cancer diagnosis. This is corroborated in the study by Lee et al.,6) wherein cervical cancer screening rate was found to significantly decline 10 years after primary cancer diagnosis. Considering all these points, primary care physicians should get actively involved in the care of cancer survivors and contribute towards addressing the setbacks related to implementation of SPC screening in cancer survivors.