Introduction

Cervical cancer is a public health problem in developing countries because it is often diagnosed in already advanced stages and presents the highest mortality rate among gynecological cancers¹,². Conversely, in recent years, the frequency of uterine cancer linked to metabolic syndrome and obesity is on the rise³,⁴.

The World Health Organization estimated that by 2018, there would be 190,667 new cases of cancer in Mexico, of which 105,051 (50.9%) cases would be affecting women. In relation to this total, 20,570 (19.5%) cases occurred in the reproductive tract with 7869 cases of cervical cancer (38.2%), 7266 (35.3%) cases of uterine cancer, 4759 (23.1%) cases of ovarian cancer, 422 (2.0%) cases of vulvar cancer, and 254 (1.2%) cases of vaginal cancer⁵.

This article shows the relative frequency of cancers of the female reproductive tract in a high-specialty cancer center for the period 2016-2017. Some of this data is compared with data published in two previous periods. The increase in the number of uterine cancers was highlighted and conclusions were drawn accordingly.

Materials and methods

During the period 2016-2017, 2185 patients were attended at the Gynecological Tumor Unit of the Oncology Service at the General Hospital of Mexico "Dr. Eduardo Liceaga." 1066 patients received a histopathological diagnosis of gynecological cancer: cervical, uterine, ovarian, vulvar, vaginal, and trophoblastic tumors.

According the respective medical records, information was obtained related to the frequency of each neoplasm, patients' age, histopathological varieties, and classification according to that of the International Federation of Gynecology and Obstetrics in its 2009 version⁶,⁷. For uterine cancers, the body mass index (BMI) was investigated, considering a BMI of 25-29.9 as overweightness and a BMI of 30.0-50 or more⁸ as obesity. The results obtained regarding the relative frequency of neoplasms and the clinical classification for cervical cancer were compared to those results reported in the previous publications for the years 1983-1984 and 2010-2011⁹,¹⁰. These results were subjected to statistical analysis using the Epi-Info^TM 6.04d system.

Results

During the period analyzed, 1026 patients were treated. Ninety (8.7%) cases corresponded to high-grade intraepithelial neoplasia (CIN 3): eighty-six cases corresponded to cervical cancer, two cases corresponded to vulvar cancer, and two cases to vaginal cancer. The relative frequency and age ranges for invasive cancers are shown in table 1. The average age for invasive cervical cancers was 50 years, 55 years for uterine cancers, and 47 years for ovarian epithelial cancer.

The relative frequency of gynecological cancers in three different periods (1983-1984, 2010-2011, and 2016-2017) is shown in table 2. The decrease in the frequency of cervical cancers among invasive cancers is highlighted, which represented 86.8% of neoplasms in 1983-1984 and 45.8% in 2016-2017 (p < 0.05). In addition, the increase in the frequency of uterine cancers was evident between the period 2010-2011 (17.9%) and also the period 2016-2017 (29.4%), p ≤ 0.0001. This situation led to its rising from third in the period 2010-2011 to the second position for the period 2016-2017. As presented in table 3, 63.9% of patients in the overall series had advanced neoplasms, (Stages II-IV). The figure includes 75.3% of invasive cervical cancers, 41.6% of uterine cancers, 68.3% of ovarian epithelial cancers, and 68.1% of vulvar cancers.

Discussion

Although a decrease in the number of cervical cancers had already been reported in our Health Centre for 2010-2011: (57.8%)¹⁰ in relation to those published for 1983-1984⁹, (86.8%), (p < 0.05); there was a significant decrease for the period 2016-2017: 57.8% vs. 45.8% (p < 0.05). However, this disease still ranks high among the leading causes of gynecological cancer admissions in hospitals and health units that serve low-income people in need of social security protection. It is likely that this decrease is related to more efficient health screening services for the disease¹¹ and an increase in coverage for its treatment, as the federal government of Mexico has implemented a free cancer care program since 2004.

Unfortunately, advanced clinical stages of the disease still predominate, because more than 60% of the population that pursues medical treatment at the General Hospital of Mexico "Dr. Eduardo Liceaga," hails from the countryside, where the necessary infrastructure for the comprehensive treatment of this type of cancer is not available¹².

The increase in frequency, reported at the General Hospital of Mexico "Dr. Eduardo Liceaga", regarding uterine cancer from 2010 to 2011¹⁰ compared to that observed in the years 1983-1984⁹: was 17.9% versus 4.5% and a rise of 29.4% in the numbers of this disease for the years 2016 and 2017, placing it second amongst all other gynecological cancers. In contrast, ovarian cancer has gone from 2^nd to 3^rd place.

We associate this change in the epidemiology of the neoplasms with the increase in obesity in recent years¹,⁴. These pathologies increased from 1975 to 2014, going from 12% to 33% in China and 39.5% to 64% in Iran. In the US and Mexico, these numbers exceed 60% for women over the age of 18¹.

There is evidence that endocrine and nutritional lifestyle factors influence the origin of 5% of cancers in women worldwide, including uterine, ovarian, and breast cancer⁴. Obese premenopausal and postmenopausal women are far more likely to develop type I endometrial cancer (up to 40%), which is of good prognosis, rather than type II, which is not associated with overweightness and obesity. In addition, type II endometrial cancer has a less favorable prognosis⁴,¹³. About 86.8% of the cases presented in this series developed type I endometrial cancer and 71.4% of these patients were overweight or obese.

The National Institute of Public Health in Mexico published in 2018 that in the past three decades, the prevalence of overweightness and obesity in Mexican children and adults has increased. At present, Mexico is one of the two countries with the highest prevalence of obesity in the world¹⁴. In 2016, the prevalence of overweightness in adults aged 20 years or older was 72.5%¹⁴.

Several studies have been published reporting that overweightness and obesity significantly increase the risk of developing ovarian epithelial cancer⁴ as well as endocervical and adenosquamous epithelial carcinoma¹⁵. According to information provided by the Institute of Public Health¹⁴, this would justify the increase observed from 6.2% to 22.1% in ovarian epithelial cancers⁹,¹⁰ and 11%¹⁵ to 18% in the numbers of cervical adenocarcinomas reported herein. These factors could also have influenced the presentation of a lower age for ovarian epithelial cancer (47 years) in relation to that of 60 years and older referred to in the literature¹⁶-¹⁸. This observation would also apply to the age of 55 years reported here for uterine cancers⁸,¹³.

As for the patient with neuroendocrine carcinoma of the endometrium reported here, which represented 0.4% of the frequency for this site, very few follow-up cases without tumor activity have been reported, which globally do not exceed 30% at 5 years.

In relation to vulvar, vaginal and trophoblastic tumors, their numbers in terms of frequency and age have remained unchanged in recent years, except for vaginal cancer, whose numbers have decreased from 1.4% to 0.2% (p = 0.003) and for trophoblastic tumors where there was also a decrease from 1.3%⁸ to 0.5%.

Conclusions

The frequency of invasive cervical cancer in relation to other cancers has decreased from 57.8% in the years 2010-2011 to 45.8% for the period 2016-2017. The frequency of cervical adenocarcinoma increased from 11% observed in the period 2005-2008 to 18% for the period 2016-2107.

The frequency of ovarian and uterine cancers increased from 19.7% and 17.9% in the period 2010 to 2011, to 22.1% and 29.4%, respectively for the years 2016 to 2017. The age of 47 and 55 years shown for these tumors in this series is lower than the age of 60 and older mentioned in the literature.

The increase in the frequency of uterine cancers reported in this series, corresponded to 86.8% cases of endometrial endometrioid adenocarcinoma. This variety has been associated with being overweight and/or obese, which was present in 71.4% of the cases studied.

About 63.9% of patients with reproductive tract cancers, who were treated at the Oncology Service of the General Hospital of Mexico "Dr. Eduardo Liceaga," had late-stage cancers.