Growth-inhibition of human-melanoma cells by vitamin-d analogs

The antiproliferative activity of 1,25(OH)(2)-vitamin D-3, and four vitamin D analogs was assessed in RPMI-7951, a human melanoma cell line which expresses the vitamin D receptor. Proliferation assays consisted of a [H-3]-thymidine incorporation assay, and a 6-day growth study. The affinity of vitamin D analogs for vitamin D receptor relative to 125(OH)(2)-vitamin D-3 was determined with a hydroxyapatite-based competitive binding assay. For the proliferation assays, cells were treated with 10(-8) M 1,25(OH)(2)-vitamin D-3, 1,25(OH)(2)-16-ene-23-yne-vitamin D-3 (Ro 23-7553), 1,25(OH)(2)-16-ene-23-yne-26,27-hexafluoro-vitamin D-3 (Ro 24-5531), 1,25(OH),-16,23Z-diene-26,27-hexafluoro-vitamin D-3 (Ro 25-5317), and 1 alpha-fluoro-25(OH)- 16-ene-23-yne-hexafluoro-vitamin D-3 (Ro 24-5583). 1,25(OH)(2)-vitamin D-3 and the four analogs all significantly inhibited melanoma cell growth (P<0.05). Competitive binding of the vitamin D analogs to vitamin D receptor ranged from 51% to 72% that of 1,25(OH)(2)-vitamin D-3, suggesting a receptor-mediated response. These results demonstrate that analogs of 1,25(OH)(2)-vitamin D-3 are potent antiproliferative agents in human melanoma cells in vitro.

Early evidence of increasing national mastectomy rates for the treatment of breast cancer

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Background: The use of mastectomy for the treatment of breast cancer has declined since initial randomized trials demonstrated equivalent survival with breast conservation therapy. Recent single institution series, however, have reported increasing mastectomy rates within the past decade.

Methods: In order to verify these findings at the national level, we analyzed data from the Surveillance, Epidemiology, and End Results database, including women diagnosed with T1-2 N0-3 M0 breast cancer from 2000 to 2007. We evaluated therapeutic mastectomy rates by the year of diagnosis and performed a multivariable logistic regression analysis to determine predictors of mastectomy as the treatment choice.

Results: A total of 228,240 patients met the entry criteria. The proportion of women treated with mastectomy decreased from 40.3% to 35.6% between 2000 and 2005. Subsequently, the mastectomy rate increased to 37.9% in 2007 (p < 0.0001). The mastectomy rate in 2007 was the highest since 2002 (38.6%). A reversal in previously declining mastectomy rates was noted in nearly all cohorts, but was most pronounced among younger women. Multivariable analysis found that age, race, marital status, geographic location, involvement of multiple regions of the breast, lobular histology, increasing tumor size, lymph node positivity, increasing grade, negative hormone receptor status, and synchronous diagnosis of an ipsilateral or contralateral breast cancer were independent predictors of mastectomy. Additionally, multivariable analysis confirmed that women diagnosed in 2007 were more likely to undergo mastectomy than women diagnosed in 2005 (HR = 1.14, CI: 1.09 to 1.18, p < 0.0001).

Conclusions: There is evidence of a reversal in the previously declining national mastectomy rates, with the mastectomy rate reaching a nadir in 2005 and subsequently rising. Further follow-up to confirm this trend and investigation to determine the underlying cause of this trend and its impact on outcomes are warranted.

Comparing survival with breast-conservation therapy or mastectomy in the management of young women with early-stage breast cancer

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Background: Previous studies have shown that young women with breast cancer treated with breast-conservation therapy (BCT) experience higher local recurrence rates. Whether such patients are better treated with mastectomy is unclear. The purpose of this study was to evaluate survival outcomes of young women with early-stage breast cancer treated with BCT or mastectomy using a large, population-based database.

Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, information was obtained for all female patients age 20 to 39 diagnosed with T1-2 N0-1 M0 breast cancer between 1990 and 2007 who underwent either BCT (lumpectomy and radiation treatment) or mastectomy. Multivariable analysis as well as a matched pair analysis were performed to compare overall survival (OS) and cause-specific survival (CSS) of patients undergoing BCT and mastectomy.

Results: 14,760 women were identified, of whom 45% received BCT and 55% received mastectomy. Median follow-up was 5.7 years (range: 0.5 to 17.9 years). Multivariable analysis revealed year of diagnosis, age, race/ethnicity, grade, PR status, tumor size, number of lymph nodes positive, and number of lymph nodes examined were independent predictors of OS and CSS while ER status was of borderline significance. After accounting for all patient and tumor characteristics, multivariable analysis found that BCT resulted in similar OS (HR: 0.93; CI: 0.83-1.04; p = 0.16) and CSS (HR: 0.93, CI: 0.83-1.05; p = 0.26) as mastectomy. Matched pair analysis, including 4,644 BCT and mastectomy patients, confirmed no difference in OS or CSS: the 5/10/15-year OS for BCT and mastectomy were 92.5%/83.5%/77.0% and 91.9%/83.6%/79.1%, respectively (p = 0.99) and the 5/10/15-year CSS for BCT and mastectomy were 93.3%/85.5%/79.9% and 92.5%/85.5%/81.9%, respectively (p = 0.88).

Conclusions: Young women with early-stage breast cancer have equivalent survival whether treated with BCT or mastectomy. These patients should be counseled appropriately regarding their treatment options, and should not choose a mastectomy based on the assumption of improved survival.

Abstract P4-11-18: CT Simulation Alone Appears To Be Appropriate for Pre-Operative Partial Breast Radiation

Introduction: Pre-operative radiotherapy is being evaluated at several centers as a method to potentially increase patient eligibility for partialbreast radiotherapy. Theoretically pre-operative radiotherapy will decrease the volume of normal tissue irradiated which could decrease the morbidity. This study was performed to determine whether CT based imaging could be used for radiotherapy planning.

Material and Methods: Between December 2008 and February 2010, 204 breast cancer patients were seen in the breast evaluation and treatment program clinic at the University of Maryland Marlene and Stewart Greenebaum Cancer Center. Patients with a new diagnosis of breast cancer and no prior treatment were included in the study if they underwent MRI of the breast and a CT, including the breast, within 30 days of each other, and images were available for review. Measurements of maximum tumor dimension obtained from CT and MRI were compared. These measurements were also compared to the maximum pathologic tumor dimension, when pathology was available. Measurements were compared using correlative paired t-tests. Associations between these measurements and T stage, tumor diameter, nodal involvement, receptor status and histologic subtype were explored. Specifically, the risk of CT underestimating the size of the tumor in the pre-operative setting was also evaluated, with a 3 mm underestimation of size chosen as significant. Results: CT and MRI images were available for 40 patients. Twelve patients who underwent imaging after receiving induction chemotherapy were excluded, leaving 28 patients for analysis. In 25 patients, CT images were obtained as part of a staging PET/CT. Pathology was available in 19 patients; nine patients received neo-adjuvant chemotherapy after imaging was obtained. The average maximum tumor dimension was 10% smaller on CT than MRI (4.25 cm (range 1.1 — 9.1 cm) versus 4.72 cm (range 1.3 — 9.0 cm)), but this difference was not statistically significant. Tumor measurements obtained by CT and MRI were only statistically different in the presence of lobular carcinoma (p=0.049). The CT underestimated the MRI measurement by greater than 3 mm in 9 out of 28 (32.14%) patients, six of whom had extensive calcifications on mammogram. When the maximum tumor dimension obtained from CT was compared to pathological size, CT underestimated the pathologic tumor size by greater than 3 mm in only 4 out of 19 (21.1%) patients. All 4 patients had pathologic T3 tumors and were node positive. For comparison, the MRI similarly underestimated the tumor size in 3 of these 4 cases. Limiting our analysis to tumors less than 3 cm in diameter, only 1 out of 7 patients had a pathologic tumor size that was 3 mm greater than the maximum tumor dimension obtained from CT imaging.

Conclusions: Measurements of maximum tumor dimension on CT are on average 10% smaller than measurements obtained from MRI, although not statistically different. The risk of underestimating pathologic maximum tumor dimension was similar for CT and MRI. The risk appeared to be less for infiltrating ductal carcinoma and tumors &lt; 3 cm. CT based treatment planning for pre-operative partial breast radiotherapy seems appropriate although additional data is needed to confirm these findings.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-18.

Abstract P4-11-11: Preoperative Radiotherapy Increases Eligibility for Partial Breast Irradiation by Significantly Reducing Normal Tissue Exposure

Introduction: External-beam accelerated partial breast irradiation (EB-APBI) is the most common technique used on NSABP B-39 primarily due to the non-invasive nature of the treatment. Many patients thought to be eligible for EB-APBI become ineligible at the time of planning due to inability to meet dose-volumetric constraints. EB-APBI in the preoperative setting will reduce the volume of normal tissue treated potentially increasing the number of patients eligible for APBI. This study tested the hypothesis that pre-operative EB-APBI will not only decrease target volumes but will decrease normal tissue exposure significantly increasing eligibility for APBI.

Materials and Methods: Forty patients with 41 previously treated early stage breast cancers (tumors ≥4 cm) were retrospectively analyzed from a prospective cohort. Imaging studies (MRI, US and mammogram) were utilized to create a spherical pre-op tumor volume using the largest reported dimension centered within the previously contoured lumpectomy cavity (LPC). Plans were created and optimized for each patient using the pre-operative tumor volume (pre-op) and LPC (post-op) using NSABP B-39 guidelines. Dose-volumetric constraints were analyzed between the cohorts using a t-test analysis. The primary end-point was to evaluate for differences in patient eligibility and normal tissue exposure.

Results: The median tumor volume was 93 cc (range 24-570 cc) and 250 cc (range 46-879 cc) in the pre-and post-operative setting respectively. This reduction in tumor volume translated into an increase in patient eligibility for EB-APBI with 35/41 (85%) cases being eligible for EB-APBI in the preop setting versus 18/41 (44%) cases in the post-op setting (p=0.0002). In the pre-op setting 6 cases were ineligible due to violation of one constraint by 5% and no case violated multiple constraints. In the post-op setting, 12 cases had 1 and 11 cases multiple reasons for ineligibility due to exceeding dose constraints by 5%. The most common reason for ineligibility in both groups was &gt; 60% of the ipsilateral breast volume receiving 50% of the dose. The mean volume of ipsilateral breast receiving 50% of the dose was 42% and 63% in the pre-and post-op groups respectively. The mean contralateral breast dose and ipsilateral lung V20 in the pre-and post-op groups were 1 versus 4% and 3 versus 9%. All DVH criteria were statistically significantly improved in the pre-op setting including heart V5 and V40, ipsilateral breast V5, V20, V50 and V80, contralateral breast dose, chest wall V5, V10 and V20; ipsilateral lung V5, V10, V20 and volume of skin receiving 50% of the dose. Contralateral lung dose and thyroid max dose were not significantly different between plans.

Conclusions: Administration of EB-APBI in the pre-op setting decreases the size of the target volume which significantly increases the utility of APBI nearly doubling the eligibility for APBI in this cohort. The largest benefit is seen by reducing the volume of breast receiving 50% of the dose. This decreased dose to normal tissues will potentially result in decreased morbidity and improved cosmesis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-11.

Improved models of stellar core collapse and still no explosions: what is missing?

Two-dimensional hydrodynamic simulations of stellar core collapse are presented which for the first time were performed by solving the Boltzmann equation for the neutrino transport including a state-of-the-art description of neutrino interactions. Stellar rotation is also taken into account. Although convection develops below the neutrinosphere and in the neutrino-heated region behind the supernova shock, the models do not explode. This suggests missing physics, possibly with respect to the nuclear equation of state and weak interactions in the subnuclear regime. However, it might also indicate a fundamental problem with the neutrino-driven explosion mechanism.

Incidental liposarcomas identified during hernia repair operations

BACKGROUND AND OBJECTIVES

Since the inguinal region communicates with the retroperitoneum, both retroperitoneal as well as de novo spermatic cord liposarcomas may be detected during hernia repair operations. We assessed the incidence of liposarcomas presenting at hernia repair in our hospital.

METHODS

We performed a clerical review of pathology reports on adult tissue accessioned during hernia repair operations and reviewed operating room logs to obtain information concerning the total number of hernia repair operations (since some operations afford no accessioned tissue).

RESULTS

Between 1992 and 1997, 1,736 adult hernia repair specimens were accessioned from approximately 2,000 operations. Among these, 22% had an associated cord lipoma; 2 cases were well-differentiated liposarcomas. These were from males aged 56 and 64 years in contrast to the mean age of 35 years for cord lipoma and measured 13 and 10 cm, whereas the mean size for cord lipomas was 5.5 cm. One of the liposarcomas had radiographic evidence of extension from a retroperitoneal lesion; the other appeared confined to the groin. On surgical exploration, the lesion was restricted to the spermatic cord region in both cases despite the suggestion of retroperitoneal extension/involvement in one.

CONCLUSIONS

Incidental liposarcomas identified during hernia operations are rare (<0.1% at our institution) but their presence merits histologic evaluation of adipose tissue from these cases. However, if efforts to contain costs are implemented and histologic review of such tissue is deemed generally unrewarding, large (>10 cm) fatty masses from this area should still be sampled.

TNM staging of pancreatic carcinoma using helical CT

OBJECTIVE

The purpose of this study was to determine the accuracy of helical CT scanning in predicting the stage of carcinoma of the exocrine pancreas using TNM staging guidelines and in predicting resectability of carcinoma of the exocrine pancreas.

MATERIALS AND METHODS

Twenty-six patients with proven adenocarcinoma of the pancreas underwent uniphasic or biphasic helical CT scanning. Two observers unaware of the patient's surgical stage evaluated the CT examinations using the TNM system (with specific assessment and description of disease sites). In addition, the two observers rated confidence of nonresectability using a 5-point scale (ranging from 1, definitely resectable, to 5, definitely not resectable). Observer results and preoperative interpretations were compared with surgical findings.

RESULTS

Nineteen of 26 patients had nonresectable disease. The combined observer scores showed correct determination of T stage in 77% of patients, of N stage in 58%, and of M stage in 79%. The overall accuracy in determining lack of resectability was 96% and 84% for the two observers. All errors in determining resectable versus nonresectable disease occurred when the observer was not maximally confident of his or her diagnosis.

CONCLUSION

Helical CT is an effective screening technique for assessing T and M stages of pancreatic carcinoma. However, helical CT is poor at detecting regional lymph node involvement. In patients with equivocal T-stage findings (such as questionable venous involvement), other studies such as endoscopic sonography may be of value.

The effect of hyperthermia and verapamil on primary and metastatic colon adenocarcinoma cell-lines - inhibition of proliferation, cell-cycle distribution and onset of apoptosis

Administration of the combination of hyperthermia and verapamil significantly decreased proliferation of HT-29 and SW-620 cells while hyperthermia or verapamil alone did not cause such growth inhibition. DNA histograms showed no significant changes in the cell cycle distribution of either cell line after hyperthermia treatment. After the administration of verapamil, a significant increase in both cell lines of the G(2)-M fraction was seen at 6, 20, and 30 hours in comparison to control with a concomitant decrease in G(1) phase population. The combination of hyperthermia and verapamil resulted in an accumulation of cells in G(2)-M phase with subsequent release from the arrest and appearence the cells showing fragmentation of chromatin into nucleosomal oligomers, the hallmark of programmed cell death (apoptosis).

A method including edge effects for the estimation of radioimmunotherapy absorbed doses in the tumor xenograft model

The temporal relationship of radiolabeled monoclonal antibody (Mab) uptake to tumor size in a nude mouse human colon cancer xenograft model (LS174T) was evaluated as an aid to developing a method for estimation of radioimmunotherapy absorbed dose. Tumors of heterogeneous size were treated with 4.4 MBq (120 microCi) of 90Y-labeled anti-Carcinoembryonic Antigen Mab (90Y-ZCE025). Regression analysis demonstrated an inverse log-log relationship of antibody uptake (%ID/g) to tumor mass in four time intervals investigated (N > 10 points/interval):12-24 h, 2-3 d, 5-7 d, and 10-14 d. Curves of predicted radionuclide concentration vs time were then constructed for a range of constant tumor sizes. Xenograft radiation dose was obtained by temporal integration of each curve and application of appropriate dose estimation formulas. For each assumed tumor mass, an edge correction for loss of beta energy outside the target volume was applied assuming a spherical tumor shape. Estimated average absorbed doses were found to vary only from 13.8-10.3 Gy for a 20-fold change in tumor sizes (0.1-2.0 g, respectively). Such constancy of dose may explain xenograft stasis observed by our group in earlier experiments at this level of administered 90Y activity.

Acidosis and hepatic portal venous gas: indications for surgery in necrotizing enterocolitis

A retrospective review of cases of necrotizing enterocolitis seen at the Children's Hospital National Medical Center during the past 5 years was performed to identify factors that indicate a need for surgical intervention. The study group consisted of 92 neonates. Persistent acidosis and hepatoportal venous gas were significantly more common in babies requiring surgery than in those who were managed medically. Other physical, radiologic, and laboratory factors did not occur more frequently in those children going to surgery. Neonates with hepatoportal venous gas or persistent acidosis should be treated aggressively, and surgical intervention should be considered early in this group. Such an approach may serve to reduce morbidity and mortality in the future.