Trophic interactions of fish communities at midwater depths enhance long-term carbon storage and benthic production on continental slopes.

Biological transfer of nutrients and materials between linked ecosystems influences global carbon budgets and ecosystem structure and function. Identifying the organisms or functional groups that are responsible for nutrient transfer, and quantifying their influence on ecosystem structure and carbon capture is an essential step for informed management of ecosystems in physically distant, but ecologically linked areas. Here, we combine natural abundance stable isotope tracers and survey data to show that mid-water and bentho-pelagic-feeding demersal fishes play an important role in the ocean carbon cycle, bypassing the detrital particle flux and transferring carbon to deep long-term storage. Global peaks in biomass and diversity of fishes at mid-slope depths are explained by competitive release of the demersal fish predators of mid-water organisms, which in turn support benthic fish production. Over 50% of the biomass of the demersal fish community at depths between 500 and 1800 m is supported by biological rather than detrital nutrient flux processes, and we estimate that bentho-pelagic fishes from the UK-Irish continental slope capture and store a volume of carbon equivalent to over 1 million tonnes of CO2 every year.

Mild ductal atypia after large-core needle biopsy of the breast: is surgical excision always necessary?

BACKGROUND: The aim of the current study was to identify a select group of patients with mild atypia who do not need surgical excision after large-core needle biopsy (LCNB) of the breast. METHODS: Nineteen (70%) of 27 patients with ductal atypia found on LCNB had subsequent surgical excision. These 19 patients were retrospectively assigned to 3 groups according to the severity of the atypia found, which was compared with the final pathologic specimen after surgical biopsy. RESULTS: Cancer was identified through surgical biopsy in 6 (32%) of 19 patients. The severity of atypia seen on the LCNB specimen strongly correlated with subsequent cancer identification (P<.01). Two (33%) of 6 patients in group 2 (true atypical ductal hyperplasia [ADH]) and 4 (80%) of 5 patients in group 3 (severe ADH, borderline ductal carcinoma in situ) had cancer after surgical biopsy. No cancer was found after surgical biopsy in 8 patients in group 1 (mild atypia, not meeting criteria for ADH). CONCLUSIONS: The results of this study suggest that surgical excision can be avoided after LCNB of the breast in patients with only mildly atypical lesions that do not meet criteria for ADH. Patients with true ADH should continue to have surgical excision.

Lack of defective expression of the ATM gene in sporadic breast cancer tissues and cell lines.

Homozygous mutations of the gene mutated in ataxia telangiectasia (ATM) causes the AT syndrome, a pleiotropic phenotype that includes an increased risk of cancer. Most of the known mutations at the ATM gene lead to truncations which are usually associated with instability of mRNA and protein. A decrease or loss of ATM protein expression is associated with specific lymphoid malignancies in AT and non-AT patients. ATM is located within a region in chromosome 11q22-23 that is frequently undergoing loss of heterozygosity in sporadic breast cancer. Epidemiological studies estimated a 4-fold increase in breast cancer risk in heterozygous women. However, direct mutational analysis failed to clearly support a role for mutant ATM alleles in breast carcinogenesis. If ATM does have a suppressor role in this tissue, one would expect deficient ATM expression. We therefore tested the hypothesis that the expression of the ATM gene is reduced in sporadic breast cancer. We determined ATM transcript levels using competitive RT-PCR on 89 randomly selected sporadic breast cancer samples and 29 normal breast tissues. Of these, 11 were matched normal/cancer pairs. We also evaluated 7 breast cancer cell lines. Deficiency in ATM expression was not observed. Of the 11 matched pairs, 7 tumors expressed mildly higher levels, 3 tumors expressed the same amount and only 1 tumor expressed <50% of the normal match. In addition, 3 cancers with tumor-associated LOH of the ATM gene expressed higher mRNA levels in the tumors than in their normal tissue matches, suggesting that no correlation exists between tumors with LOH and decreased ATM expression. In summary, our results do not support a suppressor role for ATM in the development of sporadic breast cancer.

Cancer surgery in the elderly.

The incidence of most cancers increases with age. Although the risk for surgery increases in elderly patients who have comorbidities, evaluations of risk can allow interventions that may decrease morbidity and mortality. Appropriate treatments should be offered to the elderly until studies demonstrate the elderly can safely be managed differently from younger patients. The elderly should not be denied adequate treatment simply because of age.

External compression dressing versus standard dressing after axillary lymphadenectomy.

BACKGROUND: Closed-catheter drainage after axillary lymph node dissection (ALND) for breast cancer may constitute a significant inconvenience to the recovering patient, and may also serve as portals of entry for bacteria. Any intervention that could reduce the volume and duration of postoperative drainage would be beneficial. The purpose of this study was to determine whether an external compression dressing after ALND would decrease postoperative drainage, afford earlier drain removal, and reduce subsequent seroma formation. PATIENTS AND METHODS: One hundred thirty-five women undergoing definitive surgical treatment for breast cancer were randomized to receive a compression dressing (n = 66) or standard dressing (n = 69). They were also stratified for modified radical mastectomy (MRM; n = 74) or breast conservation therapy (BCT; n = 61). All patients had ALND. The compression dressing consisted of a circumferential chest wrap of two 6-inch Ace bandages, held in place by circumferential Elastoplast bandage, and it was applied by the same nurse. This dressing remained intact until postoperative day 4. Patients in the standard dressing group (control) were fitted with a front-fastening Surgibra only. Drains were removed when the total daily amount was <50 cc. Postoperative drainage volume, total days with drain, and frequency of seroma formation were recorded for each patient. RESULTS: After 4 days, wound drainage in both groups was nearly identical (compression = 490 cc, standard = 517 cc; P = 0.48). Total days with drain were also similar (compression = 6.4 days, standard = 6.1 days; P = 0.69). The compression dressing did not reduce seroma formation. In fact, there was a statistically significant increase in the number of seroma aspirations per patient in the compression group (compression = 2.9, standard = 1.8; P <0.01). The increase in seroma aspirations was more significant in MRM patients (compression = 3.1, standard = 1.7; P <0.01) than in BCT patients (compression = 2.6, standard = 1.8; P = 0.20). CONCLUSIONS: External compression dressing fails to decrease postoperative drainage and may increase the incidence of seroma formation after drain removal. Thus, routine use of a compression dressing to reduce postoperative drainage after ALND for breast cancer is not warranted.

Sentinel lymph node biopsy in breast cancer: initial experience at Memorial Sloan-Kettering Cancer Center.

BACKGROUND: Sentinel node biopsy (SNB) has emerged as a potential alternative to routine axillary dissection in clinically node-negative breast cancer. STUDY DESIGN: From September 1995 to June 1996 at Memorial Sloan-Kettering Cancer Center, 60 patients with clinically node-negative cancer underwent SNB, which was immediately followed by standard axillary dissection. Both blue dye and radioisotope were used to identify the sentinel node. SNB was compared with standard axillary dissection for its ability to accurately reflect the final pathologic status of the axillary nodes. RESULTS: The sentinel node was successfully identified by lymphoscintigraphy in 75% (42 of 56), by blue dye in 75% (44 of 59), by isotope in 88% (52 of 59), and by the combination of blue dye and isotope in 93% (55 of 59) of all 59 evaluable patients. Of the 55 patients in this study where sentinel nodes were identified, 20 (36%) were histologically positive. The sentinel node was falsely negative in three patients, yielding an accuracy of 95%. SNB was more accurate for T1 (98%) than for T2-T3 tumors (82%). CONCLUSIONS: Lymphatic mapping is technically feasible, reliably identifies a sentinel node in most cases, and appears more accurate for T1 tumors than for larger lesions. Blue dye and radioisotope are complementary techniques, and the overall success of the procedure is maximized when the two are used together.