Predicting axillary nodal positivity in 2282 patients with breast carcinoma.

Axillary lymph node status continues to be the single most important prognostic variable for breast cancer survival despite significant progress in the molecular and genetic characterization of breast malignancies. All patients with invasive breast cancer who underwent axillary lymph node dissection as part of their treatment were evaluated by 11 clinical and pathologic factors, including the primary lesion's T category (TNM staging system), whether the lesion was clinically palpable, the presence of lymphatic or vascular invasion, nuclear grade, estrogen and progesterone receptors, S-phase, age, HER2/neu overexpression, histology (infiltrating lobular or ductal), and ploidy. A total of 2282 axillary dissections were performed: 391 in patients with ductal carcinoma in situ (DCIS) [3 of which (0.8%) contained metastases] and 1891 in patients with invasive breast cancer [680 of which (36%) contained metastases]. Multivariate analysis of patients with invasive cancer identified four factors as independent predictors of axillary lymph node metastases: lymph/vascular invasion, tumor size, nuclear grade, tumor palpability. Among a group of 189 patients with nonpalpable, non-high-grade invasive lesions 15 mm or smaller without lymph/vascular invasion, only 6 (3%) had metastases to lymph nodes. If any three of the favorable factors were present, lymph node positivity was 6% or less. Clinical and pathologic feature of the primary lesions can be used to estimate the risk of axillary lymph node metastases. Such risk assessment can be used for the treatment decision-making process.

Preoperative paclitaxel and radiotherapy for locally advanced breast cancer: surgical aspects.

INTRODUCTION: Approximately 15% of breast cancer patients present with large tumors that involve the skin, the chest wall, or the regional lymph nodes. Multimodality therapy is required, to provide the best chance for long-term survival. We have developed a regimen of paclitaxel, with concomitant radiation, as a primary therapy in patients with locally advanced breast cancer. METHODS: Eligible patients had locally advanced breast cancer (stage IIB or III). After obtaining informed consent, patients received paclitaxel (30 mg/m2 during 1 hour) twice per week for 8 weeks and radiotherapy to 45 Gy (25 fractions, at 180 cGy/fraction, to the breast and regional nodes). Patients then underwent modified radical mastectomy followed by postoperative polychemotherapy. RESULTS: Twenty-nine patients were enrolled. Of these, 28 were assessable for clinical response and toxicity, and 27 were assessable for pathological response. Objective clinical response was achieved in 89%. At the time of surgery, 33% had no or minimal microscopic residual disease. Chemoradiation-related acute toxicity was limited; however, surgical complications occurred in 41% of patients. CONCLUSIONS: Preoperative paclitaxel with radiotherapy is well tolerated and provides significant pathological response, in up to 33% of patients with locally advanced breast cancer, but with a significant postoperative morbidity rate.

First place winner of the Conrad Jobst Award in the gold medal paper competition. Nitric oxide synthase inhibitors N-monomethylarginine and aminoguanidine prevent the progressive and severe hypotension associated with a rat model of pancreatitis.

The objective of this study was to determine whether the observed vascular collapse and other pathologic features of severe pancreatitis may be related to the induction of nitric oxide synthase (NOS). The rat model of pancreatitis reported by Schmidt et al. was employed. Rats in the experimental groups received pretreatment with known NOS inhibitors, N-Monomethylarginine (NMMA) or Aminoguanidine (AG). Controls included sham-operated rats without pancreatic insult and a diseased control group which received pretreatment with normal saline (NS). Arterial blood pressure was continuously recorded with a femoral arterial catheter connected to a transducer and monitor. Fluid resuscitation for hypotension followed a strict protocol with the administration of 5.0 cc NS for sustained decreases in systolic blood pressure (SBP) below 90 mm Hg at 5-minute intervals. Laboratory parameters and histopathology confirmed the induction of pancreatitis, with 6 to 15-fold increases in serum amylase levels and an average of approximately 20% decrease in serum ionized Ca++ levels. Immunohistochemical studies of the pancreas revealed that pancreatic insult resulted in the induction of NOS. Rats in the saline control group (n = 5) became hypotensive (SBP less than 90 mm Hg) between 3 and 4 hours post pancreatic insult and required an average of 110.0 cc (3-4 x blood volume) of NS fluid resuscitation. Rats which were not resuscitated (n = 5) did not survive.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural studies on the inactivation of gamma-glutamylcysteine synthetase by the disulphide analogues of radioprotective cysteamine derivatives. Effects of aminoalkyl and hydroxyalkyl chain length and beta beta-bis-dimethylation.

Disulphide compounds have been shown to inactivate gamma-glutamylcysteine synthetase, the rate-limiting enzyme for GSH synthesis. Such compounds bind to a cysteine residue at or near the glutamate-binding site of the enzyme. This phenomenon is thought to be responsible for the synergistic toxicity of the thiophosphate radio- and chemo-protective agent WR2721 and the oxygen-radical generator 6-hydroxydopamine (2,4,6-trihydroxyphenethylamine). 6-Hydroxy-dopamine enhances conversion of WR2721 into its disulphide metabolite NN'-bis-(3-aminopropyl)cystamine, which, in turn, paralyses the synthetase. In an effort to identify radio- and chemo-protective thiols and thiol derivatives that do not have this toxicity, we have begun to define the structure-activity relationship that governs inactivation of the enzyme by analogues of WR2721 disulphide. NN'-Bis(aminoalkyl)cystamines and bis(hydroxyalkyl)cystamines with an alkyl chain length of C5 or greater are not inactivators of the synthetase. That this is not due solely to the size of these compounds is shown by the potent inactivation of the enzyme by SAPH3 disulphide, an extremely bulky cystamine analogue. beta beta-Bis-dimethylation of the cystamine portion of the molecule also obviates inactivation. This is almost certainly due to steric interference with disulphide interchange. These findings may facilitate the safe adjunctive use of the thiol counterparts of such compounds with oxygen-radical-generating chemotherapeutic agents, and may shed light on the structure of the region of the synthetase adjacent to the glutamate-binding site.