ABSTRACT
BACKGROUND AND PURPOSE: Adjuvant breast cancer therapy may reduce maximal muscle strength, muscle mass, and functional performance. Although maximal strength training (MST) has the potential to counteract this debilitating outcome and is shown to be superior to low- and moderate-intensity strength training, it is unknown if it can elicit effective adaptations in patients suffering treatment-induced adverse side effects. METHODS: Fifty-five newly diagnosed stage I to III breast cancer patients (49 ± 7 yr) scheduled for adjuvant therapy were randomized to MST or a control group. The MST group performed 4 × 4 repetitions of dynamic leg press at approximately 90% of one-repetition maximum (1RM) twice a week for 12 wk. RESULTS: In the MST group, improvements in 1RM (20% ± 8%; P < 0.001) were accompanied by improved walking economy (9% ± 8%) and increased time to exhaustion during incremental walking (9% ± 8%; both P < 0.01). Moreover, the MST group increased 6-min walking distance (6MWD; 10% ± 7%), and chair rising (30% ± 20%) and stair climbing performance (12% ± 7%; all P < 0.001). All MST-induced improvements were different from the control group (P < 0.01) which reduced their 1RM (9% ± 5%), walking economy (4% ± 4%), time to exhaustion (10% ± 8%), 6MWD (5% ± 5%), chair rising performance (12% ± 12%), and stair climbing performance (6% ± 8%; all P < 0.01). Finally, although MST maintained estimated quadriceps femoris muscle mass, a decrease was observed in the control group (7% ± 10%; P < 0.001). The change in 1RM correlated with the change in walking economy (r = 0.754), time to exhaustion (r = 0.793), 6MWD (r = 0.807), chair rising performance (r = 0.808), and stair climbing performance (r = 0.754; all P < 0.001). CONCLUSIONS: Lower-extremity MST effectively increases lower-extremity maximal muscle strength in breast cancer patients undergoing adjuvant therapy and results in improved work economy, functional performance, and maintenance of muscle mass. These results advocate that MST should be considered in breast cancer treatment.
Subject(s)
Breast Neoplasms/rehabilitation , Lower Extremity/physiology , Muscle Strength , Resistance Training/methods , Adult , Body Mass Index , Breast Neoplasms/physiopathology , Breast Neoplasms/therapy , Chemotherapy, Adjuvant , Female , Humans , Mastectomy, Segmental , Middle Aged , Physical Functional Performance , Quadriceps Muscle/physiology , Radiotherapy, Adjuvant , Resistance Training/adverse effects , Thigh/anatomy & histology , Walking/physiologyABSTRACT
PURPOSE: In this report, we summarise data on BRCA1 gene analysis in Latvia to characterise criteria of genetic testing for breast and ovarian cancer susceptibility. MATERIAL/METHODS: Analysis by SSCP/HD, MALDI-TOF mass spectrometry or DNA sequencing was used for mutation detection. Mutations identified were confirmed by direct DNA sequencing. RESULTS: Out of 1068 breast and 231 ovarian cancer patients from different families: 58 carried the c.5266dupC and 43 carried the c.4035delA mutations. Every 4th patient in our study did not report cancer in the family. The breast cancer was diagnosed earlier in carriers of the c.5266dupC than in carriers of the c.4035delA (p=0.003). The incidence of breast or ovarian cancer does not differ among the 2 mutation carriers in our patient group. The nature of the c.5266dupC mutation might be more deleterious. CONCLUSIONS: We recommend the screening of 4 founder BRCA1 mutations in all breast and ovarian cancer patients in Latvia at diagnosis of disease regardless of family history or age. The BRCA1 screening can be carried out efficiently using the MALDI-TOF mass spectrometry mutation detection method developed in the Biomedical Research and Study Centre (Riga, Latvia).