Résumé
Objectifs : Il a été démontré que les femmes ayant des implants mammaires pour fins
esthétiques ont des taux élevés de suicide, mais le risque de suicide selon le temps après la chirurgie et selon l’âge à la chirurgie nécessite d’être clarifié. De plus, plusieurs autres causes de décès parmi ces femmes doivent être clarifiées. Le but de cette étude était de combler ces lacunes.
Méthodes : Cette étude présente une analyse de 10 ans de plus de suivi d’une grande étude
de cohorte de femmes ayant reçu soit des implants mammaires pour fins esthétiques (n=24 558) ou une autre chirurgie esthétique (15 893). Plus de 70% de la cohorte a été suivi pour plus de 20 ans. La mortalité chez les femmes avec des implants mammaires a été comparée au groupe contrôle en utilisant des modèles de Poisson multivariés (Rapport de Taux de mortalité (RT)) ainsi qu’aux femmes de la population générale en utilisant le Rapport Standardisé de Mortalité (RSM).
Résultats : Des taux plus élevés de suicide ont été observés chez les femmes avec une
augmentation mammaire comparativement aux femmes de la population générale (RSM = 2,00, IC à 95% = 1,66-2,41) ainsi qu’aux femmes avec une autre chirurgie esthétique (RT de mortalité = 1,43, IC à 95% = 1,02-1,99). Nos résultats suggèrent une tendance croissante du RT de mortalité selon le temps après la chirurgie. Les femmes ayant reçu une augmentation mammaire en bas âge avaient le plus haut RT de mortalité de suicide (RT de mortalité = 1,92, IC à 95% = 1,16-3,16). Aucune différence de risque de décès de plusieurs autres causes n’a été observée lorsque les femmes avec implants mammaires ont été comparées aux femmes avec une autre chirurgie esthétique.
Conclusion : Les taux de suicide chez les femmes avec une augmentation mammaire
demeurent élevés 20 ans ou plus après la chirurgie. Davantage d’investigations sont nécessaires afin d’élucider l’augmentation possible du risque de suicide selon le temps après la chirurgie et la variation du risque selon l’âge à la chirurgie.
Abstract
Objectives: Cosmetic breast implant women have been shown to have elevated rates of
suicide, but suicide risk over time after implantation and according to age at surgery needs to be clarified. As well, clarification in risk for several other causes of death is needed. The purpose of this study is to fill these research gaps.
Methods: This study presents an extended analysis of 10 more years of follow-up of a
large Canadian cohort of women who received either cosmetic breast implants (n=24,558) or other cosmetic surgery (15,893). Over 70% of the cohort was followed for over 20 years. Mortality among implant women was compared to those of controls using multivariate Poisson models (mortality Rate Ratio (RR)) and the general female population using Standardized Mortality Ratios (SMRs).
Results: Augmented women have been shown to have elevated rates of suicide relative to
the general female population (SMR = 2.00, 95% CI= 1.66-2.41) and compared to women seeking other cosmetic surgery (RR = 1.43, 95% CI= 1.02-1.99). Our results are suggestive of an increasing trend in the mortality RR of suicide as time since implantation increases. Women who had breast augmentation at a young age were seen to have the highest suicide mortality ratio (RR = 1.92, 95% CI = 1.16-3.16). No differences were seen for several other causes of death when comparing augmented women to other cosmetic surgery women.
Conclusions: Rates of suicide among augmented women remain elevated 20 years or more
after surgery. Further work is needed to elucidate possible increase in suicide risk as time since implantation increases and variation in risk according to age at surgery.
Introduction
Mortality patterns among women with cosmetic breast implants have been reported by a number of investigators over the last decade (1-8). Given higher suicide rates observed among augmented women compared with women in the general population (1-8), psychological considerations have been of much interest (9-12). Some studies have suggested that the excess in suicide risk may change with length of time since surgery (1;6) and age at which surgery was performed (1;3;6). However, these reports have been severely limited by a small number of suicide deaths which makes it difficult to draw any solid conclusions. Given the limited evidence, suicide risk patterns over time following breast augmentation surgery and age at surgery still need to be clarified.
Studies have consistently reported that women with cosmetic breast implants are not at an increased risk of breast cancer mortality compared to women in the general population or to women with other cosmetic surgeries (1;3-8). However, clarification is needed for several other causes of death. For instance, three reports showed that women with implants have higher risks of death from respiratory diseases than women in the general population (6-8). Additionally, Lipworth et al. (6) and Koot et al. (8) reported an increased risk of lung cancer death relative to the general female population, but other studies showed no difference in risk (1;3;5;7). There is also a concern of an elevated risk of death from motor vehicle accidents (1) and several other types of injuries (4;6-8). Therefore, clarification is needed in order to understand mortality risk among women seeking breast augmentation.
In this report, we present an updated analysis after adding 10 more years of follow-up to our Canadian cohort of women with cosmetic breast implants (3). We aim to provide more evidence on the risk of suicide among women with cosmetic breast implants over a much longer period of time. Additionally, we provide further insights on several other causes of death among these women.
Methods
Study design, study population and selection criteria
The study population was detailed in our previous publication (3) and described here briefly. The cohort includes women, 18 years of age or older, who underwent bilateral cosmetic breast augmentation in the provinces of Ontario or Quebec, in Canada, between January 1, 1974, and December 31, 1989. A comparison group was assembled for the same time frame and includes women who received other common elective cosmetic surgeries: chemical peel or dermabrasion, coronal brow lift (eyebrow and forehead lift), otoplasty (ear surgery), rhinoplasty (nose surgery), rhytidectomy (face-lift), or blepharoplasty (eyelid surgery). Controls were identified through frequency matching to the breast implant recipients by year of first eligible plastic surgery, province of residence and surgeon. Eligibility criteria are detailed in our previous publication (3).
The cohorts include 40,451 women: 24,558 received breast implants (7,153 women from Ontario and 17,405 from Quebec) and 15,893 women (4,418 from Ontario and 11,475 from Quebec) received other common elective cosmetic surgeries. For both cohorts, information on year of surgery, age at surgery, personal identifying information (used only for linkage purposes) and verification of eligibility criteria was collected by review of medical (hospital or private clinic) records of all women in the cohort.
Mortality in the implant and other cosmetic surgery cohort was also compared to that of the general female population. Female mortality rates for the provinces of Ontario and Quebec were obtained from provincial vital registries (unpublished document, Chronic Disease Surveillance and Monitoring Division, Public Health Agency of Canada, Ottawa, 2011).
Ethics approval for the study was granted by the University of Toronto’s Office of Research Ethics, the ethics committee of the Centre Hospitalier Affilié universitaire de Québec’s (CHA) Saint-Sacrement Hospital and the Ethics Committee for Clinical Research of Laval University.
Ascertainment of outcomes
In our previous analysis (3), the mortality experience that occurred from the date of surgery until December 31, 1997 was reported. Mortality was assessed by linking personal identifying information of cohort members to the Canadian Mortality Database (CMDB) (13). Additional details are provided in our previous paper regarding the linkage with the CMDB (3). Mortality experience for the extended follow-up among the Quebec cohort was assessed for the period between January 1, 1998 and December 31, 2007 by linking cohort member identifiers using a deterministic linkage approach with the mortality file of Quebec held by the Quebec Institute of Statistics. Linkage of the Ontario cohort with the Ontario Mortality Database (OMDB) was performed at Cancer Care Ontario, covering the period between January 1, 1998 and December 31, 2006 using a computerized probabilistic record linkage system (14). Date of death and underlying cause of death, based on the International Classification of Diseases (ICD), 9th and 10th Revisions, were extracted from the databases. ICD 9 codes were converted to ICD 10 codes using a valid documentation
(15). Where no link was found each patient was assumed to be alive at the end of follow- up.
Statistical analysis
The calculation of person-years of follow-up for each cohort member was done from one year after the date of surgery until the earliest of date of death or December 31, 2007. The first year of follow-up was excluded from the analyses to reduce the influence that pre- existing disease at the time of surgery may have had on our comparisons. Numbers of person-years and deaths were tabulated across strata defined by study group (implant women or other cosmetic surgery women), province of residence at the time of index surgery (Quebec or Ontario), attained age (18–24, 25–29, 30–34, . . ., 75–79, ≥ 80 years), calendar period of follow-up (1974–1977, 1978–1981, . . .,1994–1997, 1998-2001, 2002- 2007), period of surgery (1974–1977, 1978-1981, 1982–1985, 1986–1989), age at surgery (18–<30, 30–<40, ≥ 40 years) and length of follow-up (1-<5, 5-<10, 10-<15, 15-<20 and ≥20 years). Attained age, calendar period of follow-up and length of follow-up were time- dependent variables because women would contribute person-years to different categories
within these variables as they were followed over time. In contrast, women would contribute person-years to only one level of the classification variables period of surgery and age at surgery. The DATAB module in the Epicure software program was used to calculate person-years of follow-up (16).
Initially, overall and cause-specific mortality rates for both the breast implant patients and the other cosmetic surgery group were compared with those for the general population. Mortality rates for the provinces of Ontario and Quebec were obtained from provincial vital statistics registries as described above. The expected numbers of deaths in the cohort were estimated by multiplying the tabulated person-years of follow-up by the corresponding overall and cause-specific mortality rate observed in the general female population according to province (Ontario or Quebec), age (by 5-year age intervals), and calendar period of follow-up (1974–1977, 1978–1981, . . ., 1994–1997, 1998-2001, 2002-2007). Mortality rate for the implant and other cosmetic surgery women relative to the general population was evaluated by calculating the standardized mortality ratio (SMR), which is the ratio of the observed-to-expected number of deaths (17) For the comparison with general female population estimates, person-years contributed for the period after 1998 were reduced by interprovincial migration rates according to province, attained age and calendar period of follow-up on the basis of migration rates observed through active follow-up of the Canadian population (18). This was done to account for interprovincial mobility. This approach has been previously applied to reduce the impact of losses to follow-up in a cohort study (19). The SMRs and their 95% confidence intervals (CIs) were calculated for overall mortality and cause-specific deaths, assuming a Poisson distribution.
Comparisons of cause-specific deaths, between the implant recipients and the other plastic surgery group were done using multivariate Poisson regression models using the mortality rate ratio (RR) as the measure of association (20). The influence of confounding factors was evaluated using a backward deletion approach (21). P values for trend were computed using the median time since surgery value for each category as a continuous variable and including a first-order interaction term of time since surgery using the median values and the main exposure variable of interest. The strength of association (mortality rate ratio)
comparing implant to other surgery group was found to vary with time since surgery if the interaction term was statistically significant based on a two-tailed alpha of <5%. These analyses were done with SAS, version 9.2.
Results
The total number of person-years accrued by the breast implant cohort (n=24,558) was 599,992; for the other cosmetic surgery cohort (n=15,893), person-years accrued reached 389,199 (Table 1). The total amount of person-years when the interprovincial migration correction was applied decreased to 596,219 and 386,881 for the implant group and the other plastic surgery patients respectively. Given this extended follow-up, more than 70% of the women in both the breast implant and other cosmetic surgery cohorts were followed for at least 20 years. As well, the number of deaths identified has more than doubled in both the implant and other cosmetic surgery women compared with our previous publication (3). This represents a total of 1179 deaths (480 in previous follow-up) among implant women and a total of 874 deaths (383 in previous follow-up) among other cosmetic surgery women.
The comparisons with the general female population (Table 2) showed a statistically significant reduction of overall mortality rate in both the implant cohort (SMR = 0.71, 95% CI = 0.67-0.76) and the other cosmetic surgery cohort (SMR = 0.60, 95% CI = 0.56-0.64). As well, significant lower than expected rates of mortality for endocrine diseases, mental disorders, circulatory diseases, respiratory diseases, digestive diseases, genitourinary diseases, overall cancers and other causes of death combined were observed among both the implant women and the other cosmetic surgery women relative to general female population estimates. However, augmented women had a statistically significant 17% (SMR = 1.17, 95 % CI = 1.02-1.33) increase in rate of lung cancer mortality compared to general female population estimates. Increased rates of suicide death were observed in both the augmented women (SMR = 2.00, 95% CI= 1.66-2.41) and the other plastic surgery women (SMR = 1.41, 95% CI= 1.05-1.86).
Internal comparisons revealed that women with breast implants have a significantly increased rate of suicide (RR = 1.43, 95% CI= 1.02-1.99) relative to other cosmetic surgery women (Table 3). Conversely, implant women were found to have a significantly lower rate of brain cancer mortality (RR = 0.47, 95% CI= 0.26-0.86). Colorectal cancer mortality was also higher among augmented women relative to women with other plastic surgery (RR = 1.67, 95% CI= 1.08-2.59).
Further analyses for suicide according to surgery characteristics were undertaken (Table 4). The results for implant women relative to females in the general population are suggestive of an increasing trend in suicide rate ratio according to the time since surgery. Specifically, the SMR for suicide increased from 1.66 (95% CI= 0.93-2.73) for 1 to 5 years after surgery, to 2.42 (95% CI = 1.61-3.49) for follow-up of 15 to 20 years after surgery. The SMR for the follow-up interval of more than 20 years after surgery was 2.15 (95% CI = 1.38-3.20). As well, the internal comparison revealed that the RR was highest for the interval of 20 years or more after surgery (RR = 2.29, 95% CI = 0.98-5.31) (p value for trend in the RR over time since surgery = 0.19).
Women who had breast augmentation at a young age (18 to <30 years of age) were found to have the highest rate ratio of suicide compared with either women in the general population (SMR = 2.63, 95% CI = 1.99-3.40) or those with other cosmetic surgeries (RR = 1.92, 95% CI = 1.16-3.16) (p value for trend in the RR over age at surgery = 0.24). Additionally, women that underwent breast implantation in the period of 1986 to 1989 had the greatest increase in the rate of suicide when compared to general female population estimates (SMR = 2.59, 95% CI = 1.91-3.30) and other cosmetic surgery women (RR = 2.92, 95% CI = 1.22-6.96).
Discussion
This extended follow-up of our Canadian cohort of women with cosmetic breast implants shows a reduced mortality rate for several causes of death among these women. In contrast, augmented women have been found to have persistently elevated rates of suicide either compared to women in the general population or other cosmetic surgery women. An
increasing trend in the suicide rate ratio as time since implantation increases, was observed. Women who had breast augmentation at a young age had the highest suicide rate ratio either compared to the general female population or those with other cosmetic surgeries. However, these findings were not statistically significant.
In our cohort, a reduced rate for overall mortality was found among women who received breast implants when compared with the general population. This finding is consistent with previous cohort studies including our previous follow-up (1-3;5). We also showed that women with cosmetic breast implants have lower rates of several specific causes of death such as endocrine diseases, mental disorders, circulatory diseases, respiratory diseases, digestive diseases, genitourinary diseases, overall cancers and other causes of death combined. Similar mortality patterns were observed among women with other cosmetic surgeries relative to the general female population, suggesting similarities with breast implant women in terms of sociodemographic and lifestyle characteristics (12;22). The reduced rates in both groups seem consistent with the fact that women undergoing cosmetic procedures have a different risk factor profile than the female general population (23). Women undergoing cosmetic procedures are recognized to be of higher socioeconomic status which is correlated with improved health status (24). This highlights the realization that women with other cosmetic surgeries are a more appropriate control group when analyzing mortality in augmented women.
An increased rate of mortality from lung cancer was observed among augmented women compared with general female population estimates which may reflect previously reported higher smoking rates among these women compared with women in the general population (23). In fact, an excess of deaths compared with the general population for lung cancer and nonmalignant respiratory diseases was seen in a previous Swedish study and authors attributed this result to differences in smoking habits (6). Interestingly, we observed a non-statistically significant increase of lung cancer mortality when comparing implant women to other cosmetic surgery women which is consistent with a previous report (1). However, this study also reported similar rates of smoking between cosmetic breast implant women and other cosmetic surgery women (1). Moreover, in our study, the increase in the rate of lung cancer
mortality varied substantially according to time since surgery (data not shown). Thus, the association of breast implantation to increased lung cancer mortality rate remains uncertain.
A statistically significant increased rate for colorectal cancer mortality and a significant decrease in brain cancer mortality were observed when comparing augmented women to the control group. However, we found in our recent extended follow-up of cancer incidence (25) that there were no differences in brain cancer incidence (Incidence rate ratio = 0.67, 95% CI: 0.38–1.16) and colorectal cancer incidence between these two groups (Incidence rate ratio = 1.14, 95% CI: 0.88–1.46), which is consistent with previous investigations (26-29). Therefore, these findings for brain cancer and colorectal cancer mortality should be tempered.
Our finding of an increased suicide rate among women with breast augmentation relative to women in the general population is in agreement with previous epidemiological studies and our earlier paper (1-8). Specifically, studies have consistently reported that the rate of suicide among these women is two- to threefold higher than expected in the general female population (1-8). The excess rate of suicide may reflect increased prevalence of underlying psychiatric problems prior to breast augmentation surgery and other risk factors for suicide among a subset of women seeking cosmetic breast augmentation (30;31). In fact, women seeking cosmetic breast augmentation have been found to have higher frequencies of psychiatric treatments and psychiatric hospital admissions before surgery, as well as varying degrees of depression, anxiety and low self-esteem compared to women not seeking augmentation (7;30). Moreover, elevated frequencies of ongoing psychiatric treatments and lower health-related quality of life in the dimension of distress after breast augmentation have also been reported among these women (9;10;32). In recent years, some authors have raised the issue of body dysmorphic disorder (BDD) as a possible explanation of the increased rate of suicide among augmented women (33;34). Specifically, BDD is a psychiatric diagnosis characterized by excessive dissatisfaction of body image that can lead to substantial distress (9) and suicidal ideation (11). In fact, the mean annual suicidal attempt rate in the U.S. population among individuals with BDD is 3 to 12 times higher than that in the general population (11). Studies have also shown that between 3% and 15% of patients undergoing cosmetic surgery have some form of BDD (35) and more than 90%
of them report either no change or a worsening of their symptoms following cosmetic surgery (9;11;12). Consequently, BDD may be a contraindication to some forms of