Two of the most important prognostic indicators for breast cancer are tumor size and extent of axillary lymph node involvement. Data on 24,740 cases recorded in the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute were used to evaluate the breast cancer survival experience in a representative sample of women from the United States. Actuarial (life table) methods were used to investigate the 5-year relative survival rates in cases with known operative/pathologic axillary lymph node status and primary tumor diameter. Survival rates varied from 45.5% for tumor diameters equal to or greater than 5 cm with positive axillary nodes to 96.3% for tumors less than 2 cm and with no involved nodes. The relation between tumor size and lymph node status was investigated in detail. Tumor diameter and lymph node status were found to act as independent but additive prognostic indicators. As tumor size increased, survival decreased regardless of lymph node status; and as lymph node involvement increased, survival status also decreased regardless of tumor size. A linear relation was found between tumor diameter and the percent of cases with positive lymph node involvement. The results of our analyses suggest that disease progression to distant sites does not occur exclusively via the axillary lymph nodes, but rather that lymph node status serves as an indicator of the tumor's ability to spread.

Relation of tumor size, lymph node status, and survival in 24,740 breast cancer cases

Purpose Cross-talk between human epidermal growth factor receptors and hormone receptor pathways may cause endocrine resistance in breast cancer. This trial evaluated the effect of adding lapatinib, a dual tyrosine kinase inhibitor blocking epidermal growth factor receptor and human epidermal growth factor receptor 2 (HER2), to the aromatase inhibitor letrozole as first-line treatment of hormone receptor (HR) –positive metastatic breast cancer (MBC). Patients and Methods Postmenopausal women with HR-positive MBC were randomly assigned to daily letrozole (2.5 mg orally) plus lapatinib (1,500 mg orally) or letrozole and placebo. The primary end point was progression-free survival (PFS) in the HER2-positive population. Results In HR-positive, HER2-positive patients (n 219), addition of lapatinib to letrozole significantly reduced the risk of disease progression versus letrozole-placebo (hazard ratio [HR] 0.71; 95% CI, 0.53 to 0.96; P .019); median PFS was 8.2 v 3.0 months, respectively. Clinical benefit (responsive or stable disease 6 months) was significantly greater for lapatinib-letrozole versus letrozole-placebo (48% v 29%, respectively; odds ratio [OR] 0.4; 95% CI, 0.2 to 0.8; P .003). Patients with centrally confirmed HR-positive, HER2-negative tumors (n 952) had no improvement in PFS. A preplanned Cox regression analysis identified prior antiestrogen therapy as a significant factor in the HER2-negative population; a nonsignificant trend toward prolonged PFS for lapatinib-letrozole was seen in patients who experienced relapse less than 6 months since prior tamoxifen discontinuation (HR 0.78; 95% CI, 0.57 to 1.07; P .117). Grade 3 or 4 adverse events were more common in the lapatinib-letrozole arm versus letrozole-placebo arm (diarrhea, 10% v 1%; rash, 1% v 0%, respectively), but they were manageable.

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Lapatinib Combined With Letrozole Versus Letrozole and Placebo As First-Line Therapy for Postmenopausal Hormone Receptor–Positive Metastatic Breast Cancer

Lapatinib combined with letrozole versus letrozole and placebo as first-line therapy for postmenopausal hormone receptor-positive metastatic breast cancer.

Background
Breast cancer patients with tumors that are estrogen receptor (ER)-positive and/or progesterone receptor (PR)-positive have lower risks of mortality after their diagnosis compared to women with ER- and/or PR-negative disease. However, few studies have evaluated variations in the risks of breast cancer-specific mortality across ER/PR status by either demographic or clinical characteristics.

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Hormone receptor status, tumor characteristics, and prognosis: a prospective cohort of breast cancer patients.

The descriptive epidemiology of female breast cancer: an international comparison of screening, incidence, survival and mortality

Breast cancer is the most common malignancy among American women. Due to increased screening, the majority of patients present with early-stage breast cancer. The Oxford Overview Analysis demonstrates that adjuvant hormonal therapy and polychemotherapy reduce the risk of recurrence and death from breast cancer. Adjuvant systemic therapy, however, has associated risks and it would be useful to be able to optimally select patients most likely to benefit. The purpose of adjuvant systemic therapy is to eradicate distant micrometastatic deposits. It is essential therefore to be able to estimate an individual patient's risk of harboring clinically silent micrometastatic disease using established prognostic factors. It is also beneficial to be able to select the optimal adjuvant therapy for an individual patient based on established predictive factors. It is standard practice to administer systemic therapy to all patients with lymph node-positive disease. However, there are clearly differences among node-positive women that may warrant a more aggressive therapeutic approach. Furthermore, there are many node-negative women who would also benefit from adjuvant systemic therapy. Prognostic factors therefore must be differentiated from predictive factors. A prognostic factor is any measurement available at the time of surgery that correlates with disease-free or overall survival in the absence of systemic adjuvant therapy and, as a result, is able to correlate with the natural history of the disease. In contrast, a predictive factor is any measurement associated with response to a given therapy. Some factors, such as hormone receptors and HER2/neu overexpression, are both prognostic and predictive.

Prognostic and predictive factors in early-stage breast cancer.

Purpose: The main objectives of this phase I and pharmacokinetic, open-label study were to determine the optimally tolerated regimen (OTR), safety, pharmacokinetics, and clinical activity of lapatinib in combination with letrozole in patients with advanced solid malignancies. Experimental Design: Patients with advanced breast cancer with immunohistochemically detectable estrogen or progesterone receptors or other cancers were eligible. Doses of lapatinib were escalated in cohorts of three subjects from 1,250 to a maximum of 1,500 mg/d based on dose-limiting toxicities in the first treatment cycle. The letrozole dose was fixed at 2.5 mg/d. Additional patients were enrolled at the OTR dose level to further evaluate safety and for pharmacokinetic analyses. Results: Thirty-nine patients were enrolled in the study: 12 in the dose-escalation group, 7 in the OTR safety group, and 20 in the pharmacokinetic group. The OTR dose level was identified as 1,500 mg/d lapatinib and 2.5 mg/d letrozole. The most common (>25% of patients) drug-related adverse events were diarrhea (77%), rash (62%), nausea (46%), and fatigue (26%). No significant differences were observed in the pharmacokinetic variables (Cmax and AUC) of lapatinib and letrozole when coadministered compared with single-agent administration. One patient with endometrial cancer had a confirmed partial response. Conclusions: Clinically relevant doses of lapatinib in combination with letrozole were well tolerated and did not result in a pharmacokinetic interaction, and clinical antitumor activity was observed.

https://clincancerres.aacrjournals.org/content/clincanres/14/14/4484.full.pdf

A phase I and pharmacokinetic study of lapatinib in combination with letrozole in patients with advanced cancer.

3001 Background: Lapatinib is a selective and highly potent dual, competitive inhibitor of ErbB1 and ErbB2 tyrosine kinases leading to cell growth arrest and/or apoptosis in ErbB1 and ErbB2 dependent tumor cell lines and xenografts. Co-expression of ErbB2 and ER is associated with a reduced response rate to hormone therapy in breast cancer. A rational approach to treatment may be to block simultaneously both ER and ErbB2 pathways. Methods: Patients (pts) with advanced breast cancer, ER or PR +, or other tumors (e.g., ovarian, endometrial) that would be likely to respond to the combination therapy were enrolled. Escalating doses of lapatinib (1250–1500 mg/d) were administered in combination with letrozole (2.5 mg/d). Three pts were treated at each dose level, with expansion to 6 in the event of dose-limiting toxicity (DLT). Once the optimally tolerated regimen (OTR) was determined, an additional 8 - 16 pts were to be enrolled to establish the pharmacokinetic profiles of lapatinib and letrozole when adminis...

A phase I, open-label study of the safety, tolerability and pharmacokinetics of lapatinib (GW572016) in combination with letrozole in cancer patients

Breast cancer is the most common malignancy among American women. As a result of widespread screening, most patients present with operable breast cancer that is treated with curative intent. It is well established that the appropriate use of adjuvant therapy improves the disease-free and overall survival of patients with breast cancer. Adjuvant systemic therapy options include tamoxifen for hormone receptor-positive patients, and systemic polychemotherapy. It is standard clinical practice to administer adjuvant systemic therapy to patients with node-positive and high-risk, node-negative breast cancer.

Operable breast cancer

Screening mammography is associated with earlier stage disease and greater eligibility for breast conservation in women aged 4o and older with breast cancer

M. Cianfrocca

Papers

Prognostic and predictive factors in early-stage breast cancer.

A phase I and pharmacokinetic study of lapatinib in combination with letrozole in patients with advanced cancer.

A phase I, open-label study of the safety, tolerability and pharmacokinetics of lapatinib (GW572016) in combination with letrozole in cancer patients

Operable breast cancer

Screening mammography is associated with earlier stage disease and greater eligibility for breast conservation in women aged 4o and older with breast cancer