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Breast self-examination in users of the Instituto Mexicano del Seguro Social from Teapa, Tabasco, Mexico

How to cite this article: Córdova-Cadena S, González-Pozos PV, Zavala-González MA. Breast self-examination in users of the Instituto Mexicano del Seguro Social from Teapa, Tabasco, Mexico. Rev Med Inst Mex Seguro Soc. 2015 May-Jun;53(3):368-72.



Received: March 12th 2014

Accepted: February 9th 2015

Breast self-examination in users of the Instituto Mexicano del Seguro Social from Teapa, Tabasco, Mexico

Samuel Córdova-Cadena,a Patricia Vanessa González-Pozos,b Marco Antonio Zavala-Gonzálezc

aUnidad Médica Familiar 18, Instituto Mexicano del Seguro Social, Teapa

bCoordinación Clínica de Educación e Investigación en Salud, Unidad Médica Familiar 43, Instituto Mexicano del Seguro Social, Villahermosa, Centro

cSistema Estatal de Investigadores de Tabasco, Cárdenas

Tabasco, México

Communication with: Marco Antonio Zavala-González

Telephone: (55) 93 7126 4197


Objective: To establish the proportion of women of 40 years-old and more, which perform properly breast self-examination in the Family Medical Unit 18 of the Instituto Mexicano del Seguro Social from Teapa, Tabasco, Mexico, in 2011.

Methods: Cross-sectional study in a universe of 1457 women. A random sample of 127 women was obtained and aleatorily selected. Socio-demographic and hereditary variables were included and breast self-examination technique was evaluated. The information was taken from clinical files and check lists. Descriptive statistic was obtained.

Results: The mean age was 52.7 ± 9.3, with a confidence interval of 40-80 years-old. Women with a primary-school education were the largest group, representing 35.4 %. Family antecedent of breast malign tumor was found in 11 %. The mother was the most frequent parent with this background (42.9 %). Adequate breast self-examination technique was observed in 0.8 %.

Conclusions: The proportion of women that performs breast self-examination properly is very low. Associated factors were not found. Educative interventions are required in order to correct this problem.

Key words: Malign tumor; Breast; Self-examination; Descriptive epidemiology

A malignant tumor is an abnormal growth of tissue that is characterized by the loss of control of growth, as well as development and cell multiplication capable of producing metastasis.1 Because of the way they behave, tumors have colloquially been called "cancer", as it is considered by analogy that these abnormal growths of tissue hold on to healthy tissue "like the pincers of a crab".1 In this sense, the malignant tumor of the breast (ICD-10 code: C50)1 has been designated colloquially as "breast cancer", a term so widespread in the medical jargon that would be difficult to refer to it by its right name, considering that even the corresponding official Mexican law refers to the illness this way.2

Regardless of denomination, breast cancer among women is the malignant tumor of highest prevalence and incidence in the world, followed by that of the cervix. According to the latest report from the World Health Organization (WHO), in 2008 the global incidence ranged from 150 to 250 per 100,000 women.3 Mexico is one of the countries with the most new cases, and it is the leading cause of death from malignant tumors in women over 25 years.3-5

The incidence soars starting at 40 years of age,3-5 presumably due to menopausal changes, added to other risk factors such as nulliparity, first birth after age 30, early menarche, late menopause, obesity, prolonged estrogen therapy, smoking, first degree family history, and late breastfeeding.6-9

Prevention through screening is the strategy of choice.8,9 There are three strategies for early detection: breast self-examination, clinical examination, and mammography.8,9 Among these, self-examination is the cornerstone of prevention and control programs, since the sensitivity of the test is high if the correct technique is employed.2,8,9

The technique consists of two steps: inspection or observation and palpation.2,8,9 Notwithstanding the simplicity of this test, breast self-examination has low prevalence among women, between 10-30%.10-22 This low prevalence has been attributed to the social representation that tends to be held about self-examination, which in the context of an orthodox religious education is perceived as a sinful act by sexual connotation, as has been mentioned by healthy women as well as by those affected by breast cancer.10-13 In this regard, prevention and control programs face a major cultural barrier, added to lack of awareness and the improper execution of the technique.

Where the same religious beliefs are shared, several authors have evaluated the knowledge and practice of breast self-examination in various groups, and have identified some factors associated with adequate knowledge and correct practice.14-20 It has been observed that sufficient knowledge about the technique is presented in low proportion (< 60%), whereas the correct practice of the technique is even less frequent (< 50%), even among health professionals.14-20 The associated factors that have been observed include better knowledge and practices in those with a primary family history, higher level of schooling, and unorthodox practice of one’s religious beliefs.14-20  

However, the problems described may be corrected through educational strategies, of which personalized "Woman to Woman" counseling is the most effective.21,22

The approach outlined led us to ask, what is the proportion of women aged 40 and older who correctly do breast self-examination in the Unidad Médica Familiar 18 of the Instituto Mexicano del Seguro Social, in Teapa, Tabasco in 2011? This was the motive that led us to conduct this study in order to answer the question.


We conducted a study with quantitative methodology, using an observational, cross-sectional, and ambispective design. The universe consisted of 1457 women aged 40 or more, enrolled users of the Unidad de Medicina Familiar (UMF) 18 of the IMSS in Teapa, Tabasco, in August 2011. In this universe a simple random sample was studied, obtained by the formula for descriptive studies of qualitative variables in finite universes,23 through which we considered a probability of occurrence (correct breast self-exam) at 10% (p = 0.1, q = 0.9),24 and to allow a maximum error of 5% (d = 0.05), with 95% confidence (Z = 1.96), we obtained a sample of 126.5 ≈ 127 women who were randomly selected and systematized in intervals of 12.

The study included women 40 and older, enrolled users of the UMF mentioned, who went to the office of Preventative Medicine in that unit during October and November 2011. The study excluded women who met the defined inclusion criteria who also had uni- or bilateral mastectomy, absence of one or both hands, disabilities to prevent them from self-examination (e.g., blindness, mental retardation, cognitive impairment, etc.) or known breast cancer diagnosis.

Sociodemographic variables (age, marital status, occupation, religion, children, number of children, and schooling), family history of breast cancer (existence of history and family member with a history of breast cancer), and breast self-exam technique (correct technique and errors in the technique of breast self-examination) were studied.

During consultations in Preventive Medicine, researchers completed an evaluation form of the information contained in the patient’s medical record and corroborated with direct interview. The evaluation of the patient’s technique of breast self-examination was made during this event and compliance with the technique was revised using a checklist, including observation, palpation, and reference of warning signs. The technique was considered successful when the patient properly executed its entirety and enunciated all the warning signs. This instrument did not require validation as it is what the Secretaría de Salud makes standard in its Manual for Clinical Breast Examination.8

The information thus collected was systematized in a database designed for this purpose, using SPSS software, version 15.0 for Windows, with the corresponding statistical analysis consisting of descriptive statistics for all variables, and the calculation of chi-squared and odds ratios with 95% confidence (p ≤ 0.05) to measure the association of correct/incorrect self-examination technique with the variables included in the study.

This study was an investigation without risk to the integrity of its participants, since nothing was done to them nor was sensitive information handled, so informed consent was not requested, while the collected information was systematized and analyzed anonymously. It was also was approved by the Local Committee on Health Research 2701 of the Instituto Mexicano del Seguro Social.


127 women were studied with a mean age of 52.7 ± 9.3 in a range of 40-80 years. The majority declared themselves married, as seen in Table I. 95.3% (n = 121) reported having children, with an average of 3.7 ± 1.6 in a range of 1-9.

Table I Marital status of 127 women in study
Marital status Frequency % Cumulative %
Married 88 69.3 69.3
Divorced 12 9.4 78.7
Separated 9 7.1 85.8
Widow 9 7.1 92.9
Cohabitating 8 6.3 99.2
Single 1 0.8 100
Total 127 100  

The largest proportion reported primary schooling, as shown in Table II. 79.5% (n = 101) were housewives and 20.5% (n = 26) were salaried workers. Most reported to profess Catholic religion, as noted in Table III.

Table II Schooling of 127 users
Schooling Frequency % Cumulative %
Primary 45 35.4 35.4
Secondary 38 29.9 65.3
High school 22 17.3 82.6
Illiterate 13 10.2 92.8
Bachelor's degree 9 7.1 100
Total 127 100

Table III Religion professed by women in study
Religion Frequency % Cumulative %
Catholic 87 68.5 68.5
Protestant 29 22.8 91.3
Other 7 5.5 96.8
Jehovah's witness 3 2.4 99.2
Pentecostal 1 0.8 100
Total 127 100

11% (n = 14) of women reported having a family history of breast cancer. The mother was the family member mentioned most frequently, as seen in Table IV.

Table IV Family history of breast cancer of users
Family member Frequency % Cumulative percentage
Mother 6 42.9 42.9
Maternal aunt 4 28.6 71.5
Maternal grandmother 2 14.3 85.8
Sister 1 7.1 92.9
Paternal aunt 1 7.1 100
Total 14 100

Only one woman (0.8%) successfully performed the breast self-examination technique. The three components of this technique were performed properly at a ratio < 13% and correct statement of the warning signs was the rarest element (Figure 1).

Figure 1 Correctly-executed elements of breast self-examination technique

Finding one single case of properly executed technique breast self-examination, it was not actionable to obtain chi-squared or odds ratio to identify possible associated sociodemographic or family history factors.


The biases and limitations of this study should first be noted. As for limitations, the results are limited to what was observed in a single medical unit, so they are only useful in practice for this, while its scientific value as a reference is broader. Concerning biases, the Hawthorne effect may be present;25 however, the results do not suggest it, as Type I and II errors were controlled.

Regarding the results, the demographic profile of the population was a woman of about 53 years, with primary schooling, married, housewife, Catholic, with an average of four children, for whom when there is a family history of breast cancer, it is usually primary. This profile corresponds with that reported in the literature,3-9 which is a population at risk for breast cancer before for whom preventive measures should be emphasized.


The proportion of women correctly perform breast self-examination was less than 1%, well below the percentages reported in the literature, which refer to figures of 22-47%.14-20 Therefore interventions in the medical unit to enhance education on breast self-examination in patients are urgent, and, along with it, to carry out research to identify reasons why the patients exhibited such low proportion of correct breast self-examination, because based on this, the practice of self-examination is presumably just as rare, making it appropriate to consider resorting to qualitative research.

Finally, regarding the possible factors associated with correct or incorrect practice of breast self-examination, although the literature reports on various associated factors,14-20 in this series it was not possible to make the corresponding estimates, so it is not possible to confirm or deny that such associations exist.

Additional Information

This paper was presented at the Fifteenth Congreso de Investigación en Salud Pública, held in Cuernavaca, Morelos, Mexico, from March 6th to 8th 2013 under the auspices of the Instituto Nacional de Salud Pública.

  1. Organización Mundial de la Salud. Clasificación Estadística Internacional de Enfermedades y Problemas Relacionados con la Salud, 10ª Revisión. Volumen 1. Lista tabular. Capítulo 2. Tumores (neoplasias). Ginebra, Suiza: OMS; 1990.
  2. Secretaría de Salud. [México] Norma Oficial Mexicana NOM-041-SSA2-2002, Para la prevención, diagnóstico, tratamiento, control y vigilancia epidemiológica del cáncer de mama. México: Diario Oficial de la Federación; 2003.
  3. World Health Organization. Global status report of non communicable diseases 2010. Geneva, Switzerland: WHO; 2011.
  4. Robles SC, Galanis E. Breast cancer in Latin America and the Caribbean. Rev Panam Salud Pública. 2002;11(3):178-85.
  5. Secretaría de Salud. Defunciones 1979-2009 [base de datos en Internet]. México: SINAIS, 2011. Available from
  6. Calderón-Garcidueñas AL, Parás-Barrientos FU, Cárdenas-Ibarra L, González-Guerrero JF, Villareal-Ríos E, Staines-Boone T. Risk factors of breast cancer in Mexican women. Salud Publica Mex. 2000;42(1):26-33.
  7. Martínez-Garduño MD, Escobar-Chávez TJ, Soriano-Reyes C. Autocuidado de mujeres en etapa de menopausia en Toluca, México. Esc Anna Nery Rev Enferm. 2008;12(1):63-7
  8. Secretaría de Salud. Manual de exploración clínica de las mamas. Programa de prevención y control del cáncer de mama. México: Secretaría de Salud, Centro Nacional de Equidad de Género y Salud Reproductiva; 2007.
  9. Sardiñas-Ponce R. Autoexamen de mama: Un importante instrumento de prevención del cáncer de mama en atención primaria de salud. Rev Haban Cienc Med [En línea]. 2009;8(3). Available from
  10. Dias-da Silva SE, Vilela-Vasconcelos E, de Santana ME, Ataíde-Rodriges IL, Valente-Leite T, Silva dos Santos LM, et al. Representações sociales de mulheres mastectomizadas e suas implicações para o autocuidado. Rev Bras Enferm, Brazilia. 2010;63(5):727-34.
  11. Bim CR, Pelloso SM, de Barros Carvalho MD, Santos-Previdelli IT. Diagnóstico precoce do câncer de mama e colo uterino em mulheres do município de Guarapuava, PR; Brasil. Rev Esc Enferm USP. 2010;44(4):940-6.
  12. Giraldo-Mora CV, Arango-Rojas ME. Representaciones sociales frente al autocuidado en la prevención del cáncer de mama. Inv Educ Enferm. 2009;XXVII(2):191-200.
  13. García do Nascimento T, Riul da Silva S, Marinho-Machado AR. Auto-exame de mama: significado para pacientes em tratamento quimioterápico. Rev Bras Enferm, Brazilia. 2009;62(4):557-61.
  14. Hernández-Costales I, Acanda-Díaz M, Rodríguez-Torres C. Exploración de conocimientos sobre el autoexamen mamario. Rev Cubana Enfermer [En Línea]. 2003;19(3). Available from
  15. Castro-Abreu I, Rizo-Montero Y. Nivel de conocimiento de la población femenina del consultorio 6 sobre autoexamen de mama. Rev Haban Cienc Med. 2009;8(Supl 5):121-30.
  16. Carvalho-Fernández AF, Silva de Oliveira M, Rejane-Ferreira E. Práctica del autoexamen de mamas por usuarias del sistema único de salud de Ceará. Rev Cubana Enfermer. 2006;22(3). Available from
  17. Barbosa-Davim RM, de Vasconcelos-Torres G, Nunes-Cabral ML, de Lima VM, de Souza MA. Auto-exame de mama: conhecimento de usuárias atendidas no ambulatorio de uma maternidade escola. Rev Latino-am Enfermagem. 2003;11(1):21-7.
  18. Georger-Horvat EA, Greia CA, Delgado-Latapie KI, Morales DY. Nivel de conocimiento: autoexamen mamario: experiencia en dos facultades de la Universidad Nacional del Nordeste. Rev Posgrado VIa Catedra Med. 2004;140:13-5.
  19. Wirz WR, Fernández AB, Wirz FL. Autoexamen de mamas: Influencia de la educación universitaria en la realización del autoexamen de mamas. Rev Posgrado VIa Catedra Med. 2006;159:1-7.
  20. Brito CM, Bezerra FM, Nery IS. Conhecimento e práticado auto-exame de mamas por enfermeiras. Rev Bras Enferm, Brazilia. 2004;57(2):161-4.
  21. Ortega-Altamirano D, López-Carrillo L, López-Cervantes M. Estrategias para la enseñanza del autoexamen del seno a mujeres en edad reproductiva. Salud Publica Mex. 2000;42(1):17-25.
  22. Garza-Elizondo ME, Salinas-Martínez AM, Villarreal-Ríos E, Núñez-Rocha G. Autoexamen mamario. Educación e impacto. Rev Enferm IMSS. 2000;8(1):5-10.
  23. Daniel W. Bioestadística. Bases para el análisis estadístico en ciencias de la salud. 5ª ed. México: Limusa-Wiley; 2010.
  24. Quinteros-Zuñiga SR. Prevalencia de la autoexploración de mama en mujeres de edad fértil. Revista Electrónica 2006. Available from
  25. Hernández-Sampieri R. Metodología de la investigación. 5ª ed. México: McGraw-Hill Interamericana; 2010.

Conflict of interest statement: The authors have completed and submitted the form translated into Spanish for the declaration of potential conflicts of interest of the International Committee of Medical Journal Editors, and none were reported in relation to this article.

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