Incidence trends for twelve cancers in younger adults-a rapid review

Abstract

Many cancer referral guidelines use patient's age as a key criterium to decide who should be referred urgently. A recent rise in the incidence of colorectal cancer in younger adults has been described in high-income countries worldwide. Information on other cancers is more limited. The aim of this rapid review was to determine whether other cancers are also increasing in younger age groups, as this may have important implications for prioritising patients for investigation and referral. We searched MEDLINE, Embase and Web of Science for studies describing age-related incidence trends for colorectal, bladder, lung, oesophagus, pancreas, stomach, breast, ovarian, uterine, kidney and laryngeal cancer and myeloma. 'Younger' patients were defined based on NICE guidelines for cancer referral. Ninety-eight studies met the inclusion criteria. Findings show that the incidence of colorectal, breast, kidney, pancreas, uterine cancer is increasing in younger age groups, whilst the incidence of lung, laryngeal and bladder cancer is decreasing. Data for oesophageal, stomach, ovarian cancer and myeloma were inconclusive. Overall, this review provides evidence that some cancers are increasingly being diagnosed in younger age groups, although the mechanisms remain unclear. Cancer investigation and referral guidelines may need updating in light of these trends.

Fig. 1. Review PRISMA flow diagram.

The final number of articles included in the review was 98. A total of 2388 references were identified from Embase, MEDLINE and Web of Science. After the removal of duplicates, 1503 abstracts were assessed for eligibility. Of these, 225 were progressed to full-text assessment, along with other 41 publications identified through manual reference screening. After full-text review, 98 articles were identified as eligible, whilst 127 references were excluded.

Fig. 2. Recent trends in the incidence of colorectal cancer.

Annual percentage changes (APC) in incidence are reported by age group. Increases are indicated in red and decreases in blue, with darker colours corresponding to greater changes. Stable incidences are indicated in white. For simplicity, the unstratified APC is reported, when available. For studies where the unstratified APC was not available, APC is stratified by anatomical location, histological type, gender and/or two main ethnicities (Black and NHW, non-Hispanics White). When APC values were available for several time periods, only the most recent APC is included. For some studies, the upper age limit for the oldest group and the lowest age limit for the younger group were not reported in the original study. Detailed information of the time periods and age groups covered by the different studies is reported in Supplementary Table 2. The following references are not included in the figure as they cover a large number of countries: Lu et al. [9] (20 countries worldwide), Siegel et al. [7] (36 countries worldwide).

Fig. 3. Recent trends in the incidence of breast cancer.

Annual percentage changes (APC) in incidence are reported by age group. Increases are indicated in red and decreases in blue, with darker colours corresponding to greater changes. Stable incidences are indicated in white. For simplicity, the unstratified APC is reported, when available. For studies where the unstratified APC was not available, APC is stratified by gender and/or two main ethnicities (Black and NHW, non-Hispanics White). When APC values were available for several time periods, only the most recent APC is included. For some studies, the upper age limit for the oldest group and the lowest age limit for the younger group were not reported in the original study. Detailed information of the time periods and age groups covered by the different studies is reported in Supplementary Table 2.

Fig. 4. Other cancers with increasing incident trend in younger adults.

Annual percentage changes (APC) in incidence of kidney (a), uterine (b) and pancreatic (c) cancer are reported by age group. Increases are indicated in red and decreases in blue, with darker colours corresponding to greater changes. Stable incidences are indicated in white. For simplicity, the unstratified APC is reported, when available. For studies where the unstratified APC was not available, APC is stratified by gender and/or two main ethnicities (Black and NHW, non-Hispanics White). When APC values were available for various time periods, only the most recent APC is included. For some studies, the upper age limit for the oldest group and the lowest age limit for the younger group were not reported in the original study. Detailed information of the time periods and age groups covered by the different studies is reported in Supplementary Table 2.

Fig. 5. Cancers with decreasing incidence trend in younger adults.

Annual percentage changes (APC) in incidence of lung (a), bladder (b) and laryngeal (c) cancer are reported by age group. Increases are indicated in red and decreases in blue, with darker colours corresponding to greater changes. Stable incidences are indicated in white. For simplicity, the unstratified APC is reported, when available. For studies where the unstratified APC was not available, APC is stratified by gender and/or two main ethnicities (Black and NHW, non-Hispanics White). When APC values were available for various time periods, only the most recent APC is included. For some studies, the upper age limit for the oldest group and the lowest age limit for the younger group were not reported in the original study. Detailed information of the time periods and age groups covered by the different studies is reported in Supplementary Table 2.