Publicação
Padrões de tratamento e outcomes em doentes com cancro da mama T1 N0
| Resumo: | Treatment decisions in Stage I breast cancer patients are challenging. To better inform these decisions, we used quantitative research methods to 1) study survival outcomes among patients with the smallest Stage I breast cancers (tumours with less than 1 cm [T1a, b N0]), 2) examine treatment time trends among patients with Stage I breast cancers, and 3) interrogate patients regarding the minimum survival benefit needed in order to accept adjuvant chemotherapy. Using an US contemporary cohort of ~4.000 patients, we found that, there are women with T1a,b tumors who have an excellent prognosis without chemotherapy, but size and tumor subtype may identify patients in whom the rate of recurrence justifies considering chemotherapy. Expanding the analyses to all stage I breast cancer tumors (~10.000 patients), we also found out that, particularly for subtypes such as human epidermal growth factor 2 (HER2) + and hormone receptor (HR)-HER2- breast cancers, there was an increase of use of chemotherapy over the last decade, and when treated there was an increase in use of intensive chemotherapy with substantial institutional and costs variations. In this same cohort, aggressive surgical strategies were in rise, with an increasing proportion of women with unilateral cancer treated with bilateral mastectomy. In contrast, in a Portuguese cohort of ~500 patients, mostly less-intensive associations of chemotherapy were used, also with substantial institutional variations. Finally, among ~500 patients who received contemporary adjuvant chemotherapy in a randomized controlled trial, we found substantial variation in preferences regarding benefit worth undergoing chemotherapy (57% of patients would consider 6 months of chemotherapy for 2 months of benefit, whereas there was a small minority [2%] of patients that would say no to 6 months of chemotherapy for 24 months of benefit). Differences between patient and physician choices were also apparent. This study identifies subgroups of Stage I breast cancer patients to whom we can safely avoid chemotherapy and subgroups of patients to whom chemotherapy can be considered. It also highlights that in an area, which treatments may be questionable, there is substantial institutional and regional variability calling into questioning the challenges around treatment options and highlighting that these patients represent an optimal group to evaluate less toxic adjuvant regimens to maintain efficacy while minimizing short- and long term risks. Finally, it shows that eliciting preferences regarding risks and benefits of adjuvant chemotherapy is critical. |
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| Autores principais: | Luis, Inês Maria Vaz Duarte |
| Assunto: | Neoplasias da mama Tratamento primário Quimioterapia Eficácia clínica Oncologia Teses de doutoramento - 2017 |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Treatment decisions in Stage I breast cancer patients are challenging. To better inform these decisions, we used quantitative research methods to 1) study survival outcomes among patients with the smallest Stage I breast cancers (tumours with less than 1 cm [T1a, b N0]), 2) examine treatment time trends among patients with Stage I breast cancers, and 3) interrogate patients regarding the minimum survival benefit needed in order to accept adjuvant chemotherapy. Using an US contemporary cohort of ~4.000 patients, we found that, there are women with T1a,b tumors who have an excellent prognosis without chemotherapy, but size and tumor subtype may identify patients in whom the rate of recurrence justifies considering chemotherapy. Expanding the analyses to all stage I breast cancer tumors (~10.000 patients), we also found out that, particularly for subtypes such as human epidermal growth factor 2 (HER2) + and hormone receptor (HR)-HER2- breast cancers, there was an increase of use of chemotherapy over the last decade, and when treated there was an increase in use of intensive chemotherapy with substantial institutional and costs variations. In this same cohort, aggressive surgical strategies were in rise, with an increasing proportion of women with unilateral cancer treated with bilateral mastectomy. In contrast, in a Portuguese cohort of ~500 patients, mostly less-intensive associations of chemotherapy were used, also with substantial institutional variations. Finally, among ~500 patients who received contemporary adjuvant chemotherapy in a randomized controlled trial, we found substantial variation in preferences regarding benefit worth undergoing chemotherapy (57% of patients would consider 6 months of chemotherapy for 2 months of benefit, whereas there was a small minority [2%] of patients that would say no to 6 months of chemotherapy for 24 months of benefit). Differences between patient and physician choices were also apparent. This study identifies subgroups of Stage I breast cancer patients to whom we can safely avoid chemotherapy and subgroups of patients to whom chemotherapy can be considered. It also highlights that in an area, which treatments may be questionable, there is substantial institutional and regional variability calling into questioning the challenges around treatment options and highlighting that these patients represent an optimal group to evaluate less toxic adjuvant regimens to maintain efficacy while minimizing short- and long term risks. Finally, it shows that eliciting preferences regarding risks and benefits of adjuvant chemotherapy is critical. |
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