Scoping review protocol documenting cancer outcomes and inequalities for adults living with intellectual and/or developmental disabilities

INTRODUCTION

There is increasing attention on the cancer burden for adults with intellectual and developmental disabilities (IDD). Emerging evidence suggests there are differences in cancer experiences and outcomes for individuals living with IDD, from risk through survivorship. These differences may be attributed to features of the IDD, such as cognitive deficits and communication, as well as social determinants of health-like lower education levels and ableism. However, there is no comprehensive overview of the literature quantifying these potential disparities and describing the influencing factors. In this paper, we describe a scoping review protocol to systematically review published literature on cancer for adults with IDD. The purpose of this review is to identify differences in cancer risk, stage at diagnosis, treatment and survival along the cancer continuum for adults with IDD and outline potential contributing factors creating these disparities.

METHODS AND ANALYSIS

We will follow Arksey and O'Malley's expanded framework for scoping reviews to conduct this review. We will systematically search electronic databases for peer-reviewed, published journal articles to identify appropriate studies in collaboration with a health science librarian. Two reviewers will independently review titles and abstracts followed by a full-text review to determine whether it meets inclusion criteria. A data chart for collecting and sorting information will be developed in consultation with the team. Results will be collated and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews: PRISMA-Scoping Reviews. Extracted information will be summarised quantitatively and qualitatively to meet review objectives.

ETHICS AND DISSEMINATION

This scoping review will employ a methodology to identify literature related to cancer outcomes and experiences for adults with IDD. Results will be disseminated to relevant stakeholders who care for and support individuals with IDD at local, provincial and national levels and through publishing findings. By highlighting the disparities in the cancer system and gaps in the research, this scoping review can provide direction for future action.

Breast cancer and screening in persons with an intellectual disability living in institutions in France

BACKGROUND

We aimed to describe, among a population of women with intellectual disabilities (ID) living in institutions in France, the characteristics in whom breast cancer (BC) was diagnosed and of those who participated in BC screening.

METHODS

Study was performed in 2009 among a random, representative sample of women with ID living in institutions in France. Participants answered a questionnaire either directly by themselves, or with the help of an intermediary.

RESULTS

In total, 978 women with ID aged over 18 years were included, and 14 were diagnosed with BC. The incidence observed in this sample of women with ID is similar to that of the general population (standardised incidence ratio, SIR 0.857, 95% confidence interval (CI) 0.42-1.53). Average age at diagnosis was 47.8 years, and the risk of developing BC before the age of 50 was 2.03% (0.4-3.66). This risk was not significantly different from that of the general population (2.4%, 1.0-3.78). Obesity was almost twice as frequent in women who had BC as compared to those without BC (43% vs. 22.5%, P = 0.0196). Among the 310 women aged >50 years and eligible for the national BC screening programme, 238 (77%) had already had at least one mammogram, and 199 had had it within the previous 2 years. Adherence to the screening programme was 64.2% (199/310) in the participating institutions. This rate was slightly higher than the national average of 62% for the same period.

CONCLUSIONS

The results of this study show that BC is equally as frequent among women with ID living in institutions as in the general population, and occurs at around the same age. Obesity was significantly more frequent among women in whom BC was diagnosed in our study. Participation in BC screening is slightly higher among women with ID living in institutions than among the general population.

Age and stage at diagnosis: a hospital series of 11 women with intellectual disability and breast carcinoma

BACKGROUND

Breast cancer has been poorly studied in women with intellectual disability (ID), which makes designing a policy for screening the nearly 70 million women with ID in the world difficult. As no data is available in the literature, we evaluated breast cancer at diagnosis in women with ID.

METHODS

Women with ID were searched retrospectively among all women treated for invasive breast cancer in a single hospital over 18 years. Age at diagnosis was compared among the whole group of women. Tumor size, lymph node involvement, SBR grade, TNM classification, and AJCC stage were compared to controls matched for age and period of diagnosis using conditional logistic regression.

RESULTS

Among 484 women with invasive breast cancer, 11 had ID. The mean age at diagnosis was 55.6 years in women with ID and 62.4 years in the other women. The mean tumor size in women with ID was 3.53 cm, compared to 1.80 cm in 44 random controls from among the 473 women without ID. Lymph node involvement was observed in 9 of the 11 women with ID compared to 12 of the controls (OR = 11.53, p = 0.002), and metastases were found in 3 of the 11 women with ID compared to 1 of the 44 controls (OR = 12.00, p = 0.031). The AJCC stage was higher in women with ID compared to controls (OR = 3.19, p = 0.010).

CONCLUSIONS

Women with ID presented at an earlier age with tumors of a higher AJCC stage than controls despite no significant differences in tumor grade and histological type. Thus, delayed diagnosis may be responsible for the differences between disabled and non-disabled women.