Need for the study:

Breast cancer is most frequently diagnosed and one of the leading cancers amongst women worldwide. Breast cancer arises when there is growth of the malignant or cancer-causing cells in either ducts or lobules of the breast. Lump in the breast, change in the size of breast, fluid discharge from the nipple, dimpling of the skin and red or scaly patch on the breast can be the signs of breast carcinoma. Certain risk factors associated with breast cancer includes obesity, physical inactivity, alcohol, early menarche and late menopause, family history and BRCA1/ BRCA2 gene mutation. According to the site invaded by cancerous cells, breast cancer can be either invasive type which means that it is limited to one part and non-invasive type that is spreading to the other parts. Non-invasive type includes lobular carcinoma (developing in breast lobules) and ductal carcinoma (developing in breast ducts) whereas invasive type includes infiltrating lobular carcinoma, infiltrating ductal carcinoma, medullary carcinoma, mucinous carcinoma and tubular carcinoma.

Early detection and treatment increase the rate of survival of cancer patients, hence every woman should get themselves screened for breast cancer atleast once a year. Different diagnostic methods available for cancer diagnosis include mammography, needle biopsy of breast, ultrasound, PET scan (positron emission tomography), MRI and most importantly self-examination. Early intervention and treatment techniques of chemotherapy, radiation therapy, surgery and hormone therapy can help an individual lower the risks and spreading of the cancer. Chemotherapy is the administration of drugs to destroy the cancer cells and is given before surgery and is continued after surgery too. Surgery is either total mastectomy or radical mastectomy. In total mastectomy whole breast is removed whereas in radical mastectomy only the cancerous region from the breast is removed preserving the other breast tissue. Another method used is radiation therapy that destroy the microscopic tumor cells, this is often followed by surgical management, it can be either external beam radiotherapy or internal radiotherapy. Hormone therapy is used mainly when some cancer cells require estrogen for its growth, hence through hormone therapy estrogen receptors are block to prevent the growth of these cells.

Cancer patients undergoing treatment will pursue various side effects like nausea, vomiting, weight gain, sleep disturbance, fatigue and various heart related problems. These symptoms eventually affect their quality of living making a negative impact on their day-to-day activities. Fatigue has major impact on a person’s physical, social and emotional dimension on quality of life along with other factors such as age, educational level, stage of the cancer and diagnosis of the disease itself.

European Organization for Research and Treatment of Cancer (EORTC) has created several questionnaires to assess the Quality of Life (QOL) of cancer patients which is available in different languages. QLQ-30 is one of the questionnaires used to study about the QOL in breast cancer patients over past week which includes 30 items. Questionnaire contains functional scale, symptom scale and Global health status/QOL scale.

6 Minute Walk Test(6MWT) is an assessment tool for measuring functional capacity of an individual. There requires no equipment but only a straight hard pathway of 100ft to perform the test. Indicated to measure exercise capacity in patients or response to any medical intervention. Test to be avoided on individuals having angina or myocardial infarction in recent time of past few months or hypertensive patients (>180/100mmHg). Distance covered by the individual at the end of 6 minutes has to be noted along with the perceived exertion on Borgs scale.

Minimally clinical important difference (MCID) is a clinical measure to assess the changes in one’s treatment outcome which an individual identifies as important. MCID is calculated by distribution-based method and anchor-based method. Data in distribution-based method relies on standard deviation, standard error of the mean change and standard deviation of stable group whereas anchor-based method depends upon the changes reported by the patient.

Chemotherapy induced complications such as decline in cardiopulmonary fitness has major impact on QOL in patients with breast cancer. 6MWT is used as an outcome tool to assess functional capacity and has strong correlation to QOL. As per our knowledge there is no evidence estimating MCID of patients with breast cancer undergoing chemotherapy, hence this justifies the need to conduct the study.

RESEARCH QUESTION

Is there any MCID in 6 MWD in breast cancer patients from the baseline (pretreatment) and after 16 weeks?

HYPOTHESIS (H1):

There will be MCID in 6MWD in breast cancer patients from baseline (pretreatment) to 16 weeks after beginning with chemotherapy treatment.

NULL HYPOTHESIS (H0):

There will be no MCID in 6MWD in breast cancer patients from baseline (pretreatment) to 16 weeks after beginning chemotherapy treatment.