Modeling the effect of age in T1-2 breast cancer using the SEER database.

Background: Modeling the relationship between age and mortality for breast cancer patients may have important prognostic and therapeutic implications.

Methods: Data from 9 registries of the Surveillance, Epidemiology, and End Results Program (SEER) of the United States were used. This study employed proportional hazards to model mortality in women with T1-2 breast cancers.

Statistical interaction in the survival analysis of early breast cancer using registry data: role of breast conserving surgery and radiotherapy.

Purpose: To identify subgroup effects that might influence the survival results of postoperative radiotherapy.

Patients And Methods: Women selected from the Surveillance, Epidemiology, and End Results database, aged 40-69 years, with non-metastasized T1-T2 breast carcinoma, in whom axillary lymph node dissection was performed. Subgroup analyses were performed using proportional hazards models with interactions.

Percutaneous placement of marking coils before stereotactic radiation therapy of malignant lung lesions.

Purpose: To evaluate a technique for implantation of radiopaque markers in lung nodules as an aid in extracranial stereotactic radiation therapy.

Materials And Methods: An implantation technique was developed for marking intrapulmonary lung lesions by introducing a vascular coil through a coaxial needle in or near the target tumor. The markers were placed percutaneously through 15- or 20-gauge coaxial needles in 41 lesions (25 patients) under computed tomographic fluoroscopic guidance.

Ratios of involved nodes in early breast cancer.

Introduction: The number of lymph nodes found to be involved in an axillary dissection is among the most powerful prognostic factors in breast cancer, but it is confounded by the number of lymph nodes that have been examined. We investigate an idea that has surfaced recently in the literature (since 1999), namely that the proportion of node-positive lymph nodes (or a function thereof) is a much better predictor of survival than the number of excised and node-positive lymph nodes, alone or together.

Methods: The data were abstracted from 83,686 cases registered in the Surveillance, Epidemiology, and End Results (SEER) program of women diagnosed with nonmetastatic T1-T2 primary breast carcinoma between 1988 and 1997, in whom axillary node dissection was performed.

Adjuvant radiotherapy for breast cancer: effects of longer follow-up.

Background And Purpose: Recent and large trials of adjuvant radiotherapy for breast cancer have shown an overall survival benefit in favour of radiotherapy. However, with longer follow-up the late lethal toxicity of radiotherapy might reduce the overall survival benefits. In this paper we investigate more deeply this hypothesis.

The lymph node ratio as prognostic factor in node-positive breast cancer.

Background And Purpose: The clinical records of the node-positive breast cancer patients treated at our department were reviewed, to evaluate if there is a correlation between the ratio of involved axillary lymph nodes and the overall and cause specific survival.

Patients And Methods: From 1984 until July 2001, 2073 files from patients with an invasive breast carcinoma were submitted to retrospective analyses. In 810 cases, a node positive status was diagnosed.

Adjuvant radiotherapy after mastectomy for pT1-pT2 node negative (pN0) breast cancer: is it worth the effort?

Purpose: Postoperative radiotherapy (RT) for pT1-2 pN0 breast cancer was the standard treatment in our department. Since little data on the importance of RT in this subgroup are known, we reviewed the clinical records with regard to overall survival.

Material And Methods: From 1984 until 2000, 1789 files were submitted to retrospective analyses; 731 had a pT1 (n=427) or pT2 (n=304) pN0 lesion.

Omission of radiotherapy after breast-conserving surgery: survival impact and time trends.

Purpose: To evaluate the survival impact of omission of radiotherapy after breast-conserving surgery and the changes with time.

Material And Methods: Women aged 40-69 with non-metastasized T1-T2 breast cancer, who underwent breast-conserving surgery with axillary node dissection, with or without post-surgery radiotherapy, selected from the SEER (Surveillance, Epidemiology, and End Results) database. The analysis uses proportional hazards models.

Quality assurance of a system for improved target localization and patient set-up that combines real-time infrared tracking and stereoscopic X-ray imaging.

Background And Purpose: The aim of this study is to investigate the positional accuracy of a prototype X-ray imaging tool in combination with a real-time infrared tracking device allowing automated patient set-up in three dimensions.

Material And Methods: A prototype X-ray imaging tool has been integrated with a commercially released real-time infrared tracking device. The system, consisting of two X-ray tubes mounted to the ceiling and a centrally located amorphous silicon detector has been developed for automated patient positioning from outside the treatment room prior to treatment.

Functional form of the effect of the numbers of axillary nodes on survival in early breast cancer.

The change in survival in function of the numbers of involved and uninvolved axillary nodes in early breast cancer - i.e. the functional form - was investigated to search for prognostic cutoffs and to assess if ratio-based characterization of node involvement is a significant prognostic factor or not.

Effect of the number of uninvolved nodes on survival in early breast cancer.

A high number of uninvolved axillary nodes was found by some authors to be associated with poor survival in node-negative breast cancer. We searched for confirmation and extend the investigation to node-positive cases, using population data from the SEER Program. Patients selected were women aged 40-69 years, diagnosed 1988-1997, T1-T2 breast cancer, undergoing axillary dissection with 4-35 nodes examined.

Clinical use of stereoscopic X-ray positioning of patients treated with conformal radiotherapy for prostate cancer.

Purpose: To evaluate accuracy and time requirements of a stereoscopic X-ray-based positioning system in patients receiving conformal radiotherapy to the prostate.

Methods And Materials: Setup errors of the isocenter with regard to the bony pelvis were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) and infrared marker (IR) based positioning in each of 261 treatments. In each direction, the random error represents the standard deviation and the systematic error the absolute value of the mean position.

Post-surgery radiation in early breast cancer: survival analysis of registry data.

Background And Purpose: Overviews of randomized trials have shown a small survival advantage with post-surgery radiation in early breast cancer. The present study attempts to extend this observation through a systematic analysis of population data.

Materials And Methods: This retrospective cohort study used the Surveillance, Epidemiology, and End Results (SEER) data on 83,776 women with breast cancer diagnosed between 1988 and 1997, stage T1-T2, node negative or node positive.

Initial clinical experience with infrared-reflecting skin markers in the positioning of patients treated by conformal radiotherapy for prostate cancer.

Purpose: To evaluate an infrared (IR) marker-based positioning system in patients receiving conformal radiotherapy for prostate cancer.

Methods And Materials: During 553 treatments, the ability of the IR system to automatically position the isocenter was recorded. Setup errors were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) in 184 treatments.

Definition of gross tumor volume in lung cancer: inter-observer variability.

Background And Purpose: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance.

Materials And Methods: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were compared on the base of geometric volume, dimensions and extensions.