2013-340 (1)

221Ortega-Cervantes L, et al. Cancer morbidity in women. Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin 2013; 65 (3): 221-227Revista de Investigacin Clnica Revista de Investigacin Clnica Revista de Investigacin Clnica Revista de Investigacin Clnica Revista de Investigacin Clnica / Vol. 65, Nm. 3 / Mayo-Junio, 2013 / pp 221-227Versin completa de este artculo disponible en internet: www.imbiomed.com.mx

Morbidity of breast cancer and cervico-uterinecancer in women from the Occidental region of Mexico

Laura Ortega-Cervantes,* Aurora Elizabeth Rojas-Garca,* Mara de Lourdes Robledo-Marenco,*Briscia Socorro Barrn-Vivanco,* Manuel Ivn Girn-Prez,* Vernica Vallejo-Ruiz,

Juan Fernando Lpez-Flores, Agustn Carrillo-Cortez,

David Cant-De Len,|| Amelia Rodrguez-Trejo, Irma Martha Medina-Daz*

*Laboratorio de Contaminacin y Toxicologa Ambiental, Secretara de Investigacin y Posgrado. Universidad Autnoma de Nayarit.Centro de Investigacin Biomdica de Oriente, IMSS de Metepec, Puebla.

Hospital Civil Dr. Antonio Gonzlez Guevara, Servicios de Salud de Nayarit.Centro Estatal de Cancerologa, Servicios de Salud de Nayarit.

||Instituto Nacional de Cancerologa.

ARTCULO ORIGINAL

Morbilidad por cncer de mama y cervicouterinoen mujeres de la regin occidental de Mxico

RESUMEN

Antecedentes. La incidencia de cncer de mama (CaMa) ycervicouterino (CaCu) vara ampliamente entre pases. EnMxico, la mortalidad por CaMa se ha duplicado en los lti-mos 20 aos y se ha convertido en la segunda causa demuerte en mujeres de 30 a 54 aos de edad. Mientras que elCaCu representa la primera causa de muerte por neoplasiaen mujeres mayores de 25 aos. Para 2006 Nayarit ocup unode los primeros lugares a nivel nacional en mortalidad porestos tipos de cncer. Objetivo. Analizar y describir las ten-dencias actuales de distribucin demogrfica y morbilidadderivada de CaMa y CaCu en el estado de Nayarit. Materialy mtodos. Se realiz un estudio retrospectivo donde se ana-lizaron los expedientes clnicos de las pacientes a quienes seles diagnostic CaMa o CaCu en el Centro Estatal de Cance-rologa, durante enero 2006 y diciembre 2010. Resultados.Se registraron 406 pacientes con CaMa y 328 con CaCu. Elestadio clnico ms frecuente para ambos tipos de cncer fueel IIB. Los municipios de San Pedro Lagunillas y El Nayarpresentaron la mayor prevalencia de CaMa y CaCu, respecti-vamente. Conclusin. De acuerdo con los resultados obteni-dos del presente estudio, se puede sugerir que las mujeresque viven en la regin ms pobre y marginada, probablementetienen mayor posibilidad de desarrollar CaMa y CaCu.Debido a que CaMa y CaCu son prevenibles y tratables ensus etapas iniciales, la informacin demogrfica de losregistros poblacionales para estos tipos de cncer, ayudar adeterminar las tasas de incidencia y coadyuvar en la tomade decisiones.

Palabras clave. Cncer de mama. Cncer cervicouterino.Nayarit. Mxico.

ABSTRACT

Background. The incidences of breast cancer (BC) andcervico-uterine cancer (CC) vary widely from country tocountry. In Mexico, BC mortality has doubled in the last 20years to become the second leading cause of death for womenaged 30 to 54 years. CC is the most common cause of deathfrom neoplasia in women over 25 years old. In 2006, the stateof Nayarit had one of the highest mortality rates for thesetypes of cancers in Mexico. Objective. To analyze andcharacterize the current demographics and morbiditiesassociated with BC and CC in the state of Nayarit. Materialand methods. In this retrospective study, the clinicalhistories of patients who were diagnosed with BC or CC at theState Cancer Center from January 2006 to December 2010were analyzed. Results. A total of 406 patients with BC and328 patients with CC were registered. The most commonclinical stage for both cancer types was IIB. Themunicipalities of San Pedro Lagunillas and El Nayarpresented the highest prevalences of BC and CC, respectively.Conclusion. Our results suggest that women living in poorerand more marginalized regions have a higher possibility ofdeveloping BC and CC. Because BC and CC are preventableand treatable in their early stages, demographic informationfrom population records for these cancers is helpful indetermining the incidence rates and patterns and improvingdecision-making processes.

Key words. Breast cancer. Cervico-uterine cancer. Nayarit.Mexico

Ortega-Cervantes L, et al. Cancer morbidity in women. Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin 2013; 65 (3): 221-227222

INTRODUCTION

The incidences of breast cancer (BC) and cervico-uterine cancer (CC) vary widely around the world.At the global level, BC is the most frequent cancerin the female population, both in developed and deve-loping countries, and it is the second leading causeof death in the world, accounting for 10.9% of alldeaths. An estimated of 1.38 million new cases of BC(23%) were diagnosed worldwide in 2008.1 CC is thethird most common type of cancer in women andthe seventh most common cancer globally. In 2008,an estimated 530,000 new cases of CC were diagno-sed worldwide, of which 85% occurred in developingnations.1 That same year in Mexico, 13,939 and10,186 new cases of BC and CC, respectively, werediagnosed.1 In addition to sociodemographic charac-teristics, risk factors for BC include lifestyle, familyhistory of BC, genetic factors, early menarche, latemenopause, nulliparity, pregnancy at an advancedage, nutritional habits, and the use of oral contra-ceptives.2-4 For CC, risk factors include early firstsexual intercourse, infection with some types of hu-man papillomavirus, the use of oral contraceptives,cervical trauma, and certain nutritional factors.4

Between 1955 and 2005, the mortality of CC inMexican women exceeded the mortality of BC. By2006, the mortality rates of both diseases intersec-ted, and BC surpassed CC for the first time.2 In2008, 4,818 deaths from BC and 4,031 deaths fromCC were reported.5 That the same year, among all ofthe states of Mexico, the state of Nayarit had thehighest mortality rates for both cancer types (BC:9.3 and for CC: 13.4).5 The risk of dying from CC inMexico has remained higher than BC in marginali-zed populations, even as BC mortality has increa-sed; this fact is especially evident in states with ahigh level of marginalization, such as Chiapas,Oaxaca, and Guerrero.2 Conversely, in the states ofNuevo Len, Jalisco, and Baja California, and in thecapital Mexico City, which contain the largest urbancenters in Mexico, the mortality rate of BC is higherthan that of CC.2

Given that three of the 20 municipalities of Naya-rit registered urban poverty, a high or very high de-gree of marginalization and the highest mortalityrates of BC and CC, it is important to understandthe prevalence and distribution of these cancers bymunicipality. Current information about the geogra-phic patterns of these cancers in Nayarit is not avai-lable. The objective of this study was to analyze andcharacterize the current geographic distributionand morbidity rates for BC and CC in women who

were treated at the State Cancer Center in the stateof Nayarit between 2006 and 2010.

MATERIAL AND METHODS

A retrospective study was conducted. Clinical his-tories were collected for all female patients diagno-sed with BC or CC at the State Cancer Center inNayarit between January 2006 and December 2010.Women over 18 years of age who were residents ofNayarit and who had received a BC or CC diagnosisduring the study period were included. The data ob-tained from each patient included topographical andhistological diagnostic information, age, socioecono-mic level, occupation, level of education, age of me-narche, age of first sexual intercourse (AFI), age ofmenopause, harmful habits such as smoking, familyhistory of cancer, and place of residence.

The prevalence was calculated according to dataobtained from the Instituto Nacional de Estadstica,Geografa e Informtica (INEGI)6 and Consejo Na-cional de Poblacin (CONAPO).7 The mortality ra-tes were calculated according to the World HealthOrganization (WHO) guidelines.8

Statistical analysis

Based on the data, the frequency, prevalence, dis-tribution, and trends for both types of cancer werecalculated. The cancer types were statisticallyanalyzed with the Mann-Whitney U, chi-squared,and Students t tests as well as the Kruskal Wallistest. Analyses were performed using STATA soft-ware version 10.1 (StataCorp LP, College Station,TX).

RESULTS

In total, 406 patients with BC and 328 patientswith CC were included in the study. The BC and CCtypes and clinical stages for the included patientsare shown in figures 1 and 2. The prevalence of BC(Figure 1) and CC (Figure 2) increased over time;however, the prevalence of CC decreased after 2008.The most common clinical stage at diagnosis wasIIB, and patients had recurrences of both types ofcancer. BC patients ranged in age from 25 to 85years old, and CC patients ranged from 20 to85 years old (Figure 3).

Table 1 shows the sociodemographic and gyneco-obstetric characteristics of patients with BC or CC,such as the AFI, age of menarche, and age of meno-pause. The average AFIs for BC and CC patients

223Ortega-Cervantes L, et al. Cancer morbidity in women. Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin Rev Invest Clin 2013; 65 (3): 221-227

were 21 and 17.5 years, respectively (p = 0.001).The average age of menarche was 13 years old forpatients with both cancer types. A family history ofcancer (particularly maternal) was reported by45.3% of BC patients, whereas 29.6% of CC patientshad a family history of cancer. With regard to harmfulhabits, 6% of CC and BC patients habitually drankalcoholic beverages, whereas 9% of CC patientsand 8.2% of BC patients had a smoking habit. Wefound statistically significant differences (p 85

Age group


Table 1. Gynecologic characteristics and sociodemographic characteristics of patients with breast cancer (BC) and cervico-uterine cancer (CC).

Characteristic BC (n = 406) CC (n = 328) p-value

Age 52 r 12.8 53 r 14.24 0.845

Occupation


Rosamorada, and Compostela (16, 14, 12, 11, and 10cases per 10,000 individuals, respectively). The CCprevalence was greater in El Nayar, San Blas,Compostela, and Rosamorada (15, 12, 11, and 10cases per 10,000 individuals, respectively).

A statistical analysis was carried out to evaluatethe differences in CC and BC prevalence based on aregions marginalized index. The Nayarit municipa-lities were grouped using the CONAPO marginali-zed index: very high (Huajicori, El Nayar, LaYesca), moderate (Acaponeta, Tecuala, Rosamorada,Ruiz, Santiago, Santa Mara del Oro, Jala and Ama-tln de Caas), low (Tuxpan, San Blas, Compostela,Ahuacatln and San Pedro Lagunillas) or very low(Tepic, Xalisco, Ixtln del Ro and Baha de Bande-ras). The results showed differences among the re-gions for BC (p < 0.02) but not for CC (p < 0.1).

DISCUSSION

In Mexico, BC mortality has doubled in the last20 years, making it the second leading cause ofdeath in women aged 30 to 54 years.9 For CC, thethird most frequent cancer for women on a global le-vel, the incidence and mortality in Mexico havegrown in recent decades. CC is the leading cause ofdeath from neoplasia in women over 25 years old inMexico.10 The etiologies of both cancer types are ex-tremely complex and appear to involve numerousenvironmental, genetic, and endocrine factors.2 Inaddition, it is difficult to establish preventive measu-res, ensure timely diagnosis and provide accuratetreatment, all of which are dependent on improve-

ments in technological development and healthcareaccess. CC predominantly affects the lower socialclasses, whose risk of developing CC is up to five ti-mes higher than that of other social classes.11 Ac-cordingly, the incidence of CC in Hispanic andNative American women has been shown to beapproximately double the incidence in the white po-pulation. In Mexico, the increase in the incidence ofCC has been linked to a lack of effective and timelydiagnosis and treatment. Moreover, women living inrural areas of Mexico have limited access to Paptests and healthcare services in general.12

Our study showed that the prevalence of CC con-tinues to be higher in poorer and more marginalizedregions such as the municipality of Nayar, whichrecords the lowest levels of social. In the northernpart of the state of Nayarit (Acaponeta, Rosamora-da, Ruiz, San Blas, Santiago Ixcuintla, Tecuala andTuxpan) where access to healthcare is limited, mostpatients have only an elementary school education.Additionally, women tend to become sexually activequite early (ages 11-14),13 and the use pesticides inthis area is high.14 Although there has been asignificant reduction in CC mortality in Mexico asa whole, the number of CC cases continues to growin rural areas. There is an urgent need for publichealth care programs to immediately implementeffective measures addressing this situation,which has persisted over several years.

Today, BC is the leading cause of death in womenin Mexico,12 affecting both young and old. In the de-veloping world, a large proportion of BC cases occurin women under 54 years old, which is similar to

Figure 4.Figure 4.Figure 4.Figure 4.Figure 4. Prevalence ofbreast cancer and cervico-uterinecancer cases in Nayarit by muni-cipality between 2006 and 2010,per 10,000 inhabitants.

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the results observed in this study (52 years).In the past, BC was generally thought to be limitedto the higher social classes and CC to the poorerclasses; today, BC is known to affect women ofall classes. Thus, women in lower social classes or withlimited economic resources face a higher possibilityof suffering from both types of cancer in such muni-cipalities as San Blas, Rosamorada and Compostela.

Various studies have shown that the incidence ofBC is linked to family history (10 to 20% of cases),early menarche, and late menopause.15,16 In our stu-dy, 45% of the patients had a family history of can-cer, and most BC cases reported menarche at ages11-13 years and menopause at ages 50-54 years. Inaddition, early sexually activity in the patients (age21 years), which was recorded as the age of firstintercourse, was more frequent in women with CC;this finding had already been reported as a riskfactor for this type of cancer but not for BC (16).Our study also indicated that most women with BCand CC who received treatment at the State CancerCenter in Nayarit were diagnosed at an advancedclinical stage; thus, their chances of cure and survi-val were reduced. Developed nations continue to relyon early diagnosis, which is the only effective toolto keep the BC mortality rate in check, even as theincidence grows.17

It is important to assess the demographics of theincidences of BC and CC from population records tohelp determine the incidence rates and patterns forthese diseases. The results of our study showed geo-graphically specific distributions for both cancers inthe state of Nayarit. In 2009, the reported mortalityrate for CC (16.6) was above the national average(14.3), whereas the rate for BC (15.4) was below thenational average (16.4). In this study, the calculatedmortality rate for CC was 16.1%, and for BC, it was21.7%, both of which were above the national ave-rages for 2009 as reported by the INEGI.

CONCLUSION

Our results suggest that women living in poorerand more marginalized regions have a higher possi-bility of developing BC and CC. Because BC and CCare preventable and treatable in their early stages,demographic information from population recordsfor these cancers are helpful in determining the inci-dence rates and patterns and improving decision-ma-king processes.

The major limitation of the study is that thereare other institutions that treat cancer in the stateor that send patients to other states to be treated,

and in our country, the tumor registry has not beenupdated since 2003.

ACKNOWLEDGMENTS

The authors thank the State Cancer Center ofNayarit (Centro Estatal de Cancerologa de Naya-rit) for facilitating the process of reviewing the me-dical records of patients with CC and BC.

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17. Lozano-Ascencio R, Gmez-Dants H, Torres-Snchez L, et al.Tendencias del cncer de mama en Amrica Latina y El Cari-be. Sal Pub Mex 2009; 51(Suppl. 2): 147-56.

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Correspondence and reprint request:

Irma Martha Medina-DazLaboratorio de Contaminacin yToxicologa AmbientalSecretara de Investigacin y PosgradoUniversidad Autnoma de Nayarit63155, Tepic, NayaritTel.: +52-311-2118800 x 8919Fax: +52-311-2118816E-mail: [email protected]

Recibido el 1 de agosto 2012.Aceptado el 14 de febrero 2013.

2013-340 (1)

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