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December 2010, Volume 60, Issue 12

Letter to the Editor

Survival of women with locally advanced breast cancer at a teaching hospital in Lahore

Madam, the aim of this letter is to improve the understanding of a relatively new statistical technique (in context of research in our country) to acquire high quality research and health care services.
We recently read the above mentioned article in the latest issue of this journal.  Unfortunately, little is known and published about the survival of cancer patients in our country mainly because we do not have any functional central recording system (Cancer Registry) where all the cancer patients could be registered. In such a scenario, authors of the above article should be appreciated that they registered their patients and followed them up for a fairly long period to estimate the survival.
We have a few comments about this article. First, the methodology of the article does not provide any details regarding "censoring date" and it confuses further when it states that patients who presented from year 1996-2007 were included in the study. It is possible to calculate 5 and 10-years survival for those who were diagnosed before the year 2000 but the patients diagnosed after the year 2000 couldn\'t actually be included in 10-years survival analysis. In essence, censoring information would have cleared this confusion that how all the calculations have been made.
Second, on the basis of Cox proportional hazards model, authors resulted that tumour size (< 5 cm), < 3 nodes involvement  and receptor-positive disease were significant "predictors" of event free survival, while < 3 nodes involvement and receptor positive disease were the most significant "predictors" of overall survival. These findings of the study are prone to confounding effect of age, co-morbidity and even obesity (although controversial).  Substantial amount of literature has suggested that younger age has significant association with worse prognosis among breast cancer patients and the risk of death sharply increases if the patient is younger.1-6 Similarly, considerable amount of literature has revealed that presence of co-morbidities has significant association with poorer survival.4,7-9 Additionally, obesity is also linked with poor survival among breast cancer patients.10-14 All these factors increase the hazards of death among breast cancer patients, so it is crucial to include these variables in Cox-regression analysis to adjust their effects and if not included then results can be misleading.
Although, tumour size, nodal involvement and receptor positive disease all have well recognized role in cancer survival of breast cancer patients but it is essential to model the most common determinants of survival (age, co-morbidities and possibly BMI) as well, to estimate the exact size of effect for tumour and node related characteristics. This study has reported increased hazard of death from 18% to 72% due to different tumour related factors, while previous literature has reported 45% or even more than double hazard of death due to obesity and co-morbidity independently.9,13 Now the question is still there that whether the difference in hazards observed in this study can be attributed to tumour related factors or is it due to age, co-morbidity and obesity? And this could have been answered with slightly better application of Cox-regression analysis.
Kashif Shafique, Saira Saeed Mirza
Institute of Basic Medical Sciences, Dow University of Health Sciences, Karachi.


1.El Saghir NS, Seoud M, Khalil MK, Charafeddine M, Salem ZK, Geara FB, et al. Effects of young age at presentation on survival in breast cancer. BMC Cancer 2006; 6: 194.
2.Han W, Kang SY, Korean Breast Cancer Society. Relationship between age at diagnosis and outcome of premenopausal breast cancer: age less than 35 years is a reasonable cut-off for defining young age-onset breast cancer. Breast Cancer Research & Treatment 2010; 119: 193-200.
3.Livi L, Meattini I, Saieva C, Borghesi S, Scotti V, Petrucci A, et al. The impact of young age on breast cancer outcome. European Journal of Surgical Oncology 2010; 36: 639-45.
4.Siegelmann-Danieli N, Khandelwal V, Wood GC, Mainali R, Prichard J, Murphy TJ, et al. Breast cancer in elderly women: outcome as affected by age, tumor features, comorbidities, and treatment approach. Clinical Breast Cancer 2006; 7: 59-66.
5.Jayasinghe UW, Taylor R, Boyages J. Is age at diagnosis an independent prognostic factor for survival following breast cancer? ANZ Journal of Surgery 2005; 75: 762-7.
6.Gnerlich JL, Deshpande AD, Jeffe DB, Sweet A, White N, Margenthaler JA. Elevated breast cancer mortality in women younger than age 40 years compared with older women is attributed to poorer survival in early-stage disease. Journal of the American College of Surgeons 2009; 208: 341-7.
7.Houterman S, Janssen-Heijnen ML, Verheij CD, Louwman WJ, Vreugdenhil G, van der Sangen MJ, et al. Comorbidity has negligible impact on treatment and complications but influences survival in breast cancer patients. British Journal of Cancer 2004; 90: 2332-7.
8.Louwman WJ, Janssen-Heijnen ML, Houterman S, Voogd AC, van der Sangen MJ, Nieuwenhuijzen GA, et al. Less extensive treatment and inferior prognosis for breast cancer patient with comorbidity: a population-based study. European Journal of Cancer 2005; 41: 779-85.
9.Nagel G, Wedding U, Rohrig B, Katenkamp D. The impact of comorbidity on the survival of postmenopausal women with breast cancer. Journal of Cancer Research & Clinical Oncology 2004; 130: 664-70.
10.Abrahamson PE, Gammon MD, Lund MJ, Flagg EW, Porter PL, Stevens J, et al. General and abdominal obesity and survival among young women with breast cancer. Cancer Epidemiology, Biomarkers & Prevention 2006; 15: 1871-7.
11.Dal ML, Zucchetto A, Talamini R, Serraino D, Stocco CF, Vercelli M, et al. Effect of obesity and other lifestyle factors on mortality in women with breast cancer. International Journal of Cancer 2008; 123: 2188-94.
12.Imkampe AK, Bates T. Impact of a raised body mass index on breast cancer survival in relation to age and disease extent at diagnosis. Breast Journal 2010; 16: 156-61.
13.Majed B, Moreau T, Senouci K, Salmon RJ, Fourquet A, Asselain B. Is obesity an independent prognosis factor in woman breast cancer? Breast Cancer Research & Treatment 2008; 111: 329-42.
14.Majed B, Moreau T, Asselain B, Curie Institute Breast Cancer Group. Overweight, obesity and breast cancer prognosis: optimal body size indicator cut-points. Breast Cancer Research & Treatment 2009; 115: 193-203.

Journal of the Pakistan Medical Association has agreed to receive and publish manuscripts in accordance with the principles of the following committees: