Surveillance imaging with FDG-PET/CT in the post-operative follow-up of stage 3 melanoma.

Background: As early detection of recurrent melanoma maximizes treatment options, patients usually undergo post-operative imaging surveillance, increasingly with FDG-PET/CT (PET). To assess this, we evaluated stage 3 melanoma patients who underwent prospectively applied and sub-stage-specific schedules of PET surveillance. Patients and methods: From 2009, patients with stage 3 melanoma routinely underwent PET +/- MRI brain scans via defined schedules based on sub-stage-specific relapse probabilities. Data were collected regarding patient characteristics and outcomes. Contingency analyses were carried out of imaging outcomes. Results: One hundred and seventy patients (stage 3A: 34; 3B: 93; 3C: 43) underwent radiological surveillance. Relapses were identified in 65 (38%) patients, of which 45 (69%) were asymptomatic. False-positive imaging findings occurred in 7%, and 6% had treatable second (non-melanoma) malignancies. Positive predictive values (PPV) of individual scans were 56%-83%. Negative scans had predictive values of 89%-96% for true non-recurrence [negative predictive values (NPV)] until the next scan. A negative PET at 18 months had NPVs of 80%-84% for true non-recurrence at any time in the 47-month (median) follow-up period. Sensitivity and specificity of the overall approach of sub-stage-specific PET surveillance were 70% and 87%, respectively. Of relapsed patients, 33 (52%) underwent potentially curative resection and 10 (16%) remained disease-free after 24 months (median). Conclusions: Application of sub-stage-specific PET in stage 3 melanoma enables asymptomatic detection of most recurrences, has high NPVs that may provide patient reassurance, and is associated with a high rate of detection of resectable and potentially curable disease at relapse.

Modelling the role of groundwater hydro-refugia in East African hominin evolution and dispersal.

Water is a fundamental resource, yet its spatiotemporal availability in East Africa is poorly understood. This is the area where most hominin first occurrences are located, and consequently the potential role of water in hominin evolution and dispersal remains unresolved. Here, we show that hundreds of springs currently distributed across East Africa could function as persistent groundwater hydro-refugia through orbital-scale climate cycles. Groundwater buffers climate variability according to spatially variable groundwater response times determined by geology and topography. Using an agent-based model, grounded on the present day landscape, we show that groundwater availability would have been critical to supporting isolated networks of hydro-refugia during dry periods when potable surface water was scarce. This may have facilitated unexpected variations in isolation and dispersal of hominin populations in the past. Our results therefore provide a new environmental framework in which to understand how patterns of taxonomic diversity in hominins may have developed.

Lack of apoptosis of Sézary cells in the circulation following oral bexarotene therapy.

BACKGROUND: Apoptosis of malignant cells has been suggested as an important mechanism of the action of bexarotene in the treatment of cutaneous T-cell lymphoma (CTCL). OBJECTIVES: Our purpose was to examine the in vivo and in vitro responses of patients with Sézary syndrome treated with oral bexarotene and assess them for apoptosis of the Sézary cells. METHODS: Six patients with CTCL with circulating Sézary cells, participating in a clinical trial of oral bexarotene (300 mg m(-2) daily) were included in the study. Peripheral blood from the patients was analysed for in vivo and in vitro apoptosis. RESULTS: None of the six patients demonstrated in vivo apoptosis. In vitro apoptosis of Sézary cells was demonstrated in one patient following exogenous bexarotene. CONCLUSIONS: Apoptosis is not detectable in the circulation of patients with Sézary syndrome treated with bexarotene.

Haber's syndrome.

Haber's syndrome is a rare genodermatosis characterised by an early onset rosacea-like eruption associated with multiple truncal keratotic lesions. The present study reports the clinical presentation, histology and response to therapy of two cases of Haber's syndrome. The cases presented with the typical features of Haber's syndrome. Case 1 also had diffuse palmoplantar keratoderma and prominent nail cuticles, and case 2 had diffuse palmar keratoderma. These features have not been previously reported in Haber's syndrome. In the present study Haber's syndrome is reviewed, and its relationship to Dowling-Degos disease and acropigmentation of Kitamura are discussed.

Differences in age and body site distribution of the histological subtypes of basal cell carcinoma. A possible indicator of differing causes.

OBJECTIVE: To assess if there are any significant differences in the sex, anatomical site, and age distribution of patients with different histological subtypes of basal cell carcinoma (BCC). DESIGN: Histopathology reports were analyzed with respect to the subtype of BCC, site of a tumor, and age and sex of a patient. SETTING: Histopathology reports were reviewed from 1 private laboratory that derived its cases from general practitioners, surgeons, and dermatologists. PATIENTS: Patients with BCC (N = 3885) for whom case data were received by the pathology laboratory from January 2, 1991, to June 12, 1991, were included in the study. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Superficial BCCs differed from other subtypes of BCC by occurring more commonly on the trunk and in younger patients. RESULTS: The mean age (56.8 years) of the patients with superficial BCCs was significantly lower than that of the patients with other subtypes of BCC who were examined (P < .001); the mean ages of the patients with these other subtypes were as follows: nodulosuperficial BCC, 62.9 years; nodular BCC, 63.9 years; nodulomorpheic BCC, 66.1 years; and morpheic BCC, 66.0 years. The majority of superficial BCCs occurred on the trunk and limbs (73.3%), while the majority of all other subtypes occurred on the head and neck. CONCLUSIONS: Superficial BCC differs from the other subtypes of BCC in terms of patient age and tumor site, and these findings may reflect differences in the etiology.

Beneficial effects following carbon dioxide laser excision on experimental neuroblastoma.

Treatment of neuroblastoma in children consists of primary excision with adjuvant radiation and chemotherapy. When the tumor invades surrounding structures that cannot be safely excised or when distant metastasis is present, the patient has a poor prognosis. Because the CO2 laser can be used to excise malignant tumors without seeding the surrounding tissue and because the defocused beam can vaporize malignant cells, we compared partial scalpel excision and partial laser excision of C1300 murine neuroblastoma to the growth rate of residual tumor. In 25 mice, 75% of the tumor was excised with a scalpel, and in another 25, the same percentage was excised with the CO2 laser (10 W). CO2 laser excision significantly decreases the growth of residual neuroblastoma (P less than .01). However, the effect appears to be a function of increased tumor immunogenicity after laser excision rather than the increased tumor kill. We conclude that CO2 laser excision of neuroblastoma may prove to be superior to scalpel excision for primary surgical treatment of neuroblastoma.

Mechanisms of reduction of tumor recurrence with carbon dioxide laser in experimental mammary tumors.

This study compares local tumor recurrence after low energy CO2 laser wound sterilization with recurrence after scalpel, laser or electrocautery excision. Wound histologic changes were studied to understand the mechanism of the interaction between the laser and wound. Single implants of R3230AC mammary tumor were grown to an average diameter of 24 millimeters in the mammary ridge of 80 female fisher 344 rats. Rats were anesthesized with pentobarbital and randomized into groups, each with similar tumor size: scalpel (S), laser (L), laser with wound sterilization (LV), scalpel with sterilization (SV) and electrocautery (E). All surgical procedures were performed by the same surgeon with the same technique, with the exception of the instruments used. Tow rats from each group were sacrificed immediately and the wounds examined histologically. The Sharplan 1100 CO2 laser was used with a 125 millimeter hand piece in focus and in continuous wave for groups L and LV. Sterilization in groups LV and SV was performed with 5 millimeter spot size by heating the site gently without causing blanching of tissue. Excision in group E was performed with coagulating current from a monopolar cautery (Valley Lab). Rats were examined periodically for 30 days and those dying during this period were excluded from analysis. The incidence of wound recurrence was eight of 12 in group S; five of eight, L; four of 13, E; three of 12, LV, and two of nine, SV (p less than 0 .05). Histologic changes in the wound demonstrated viable tumor in all groups, with fewer areas present in groups E, SV and LV. Local thermal effects and the noncontact nature of the CO2 laser make it an effective adjunct in reducing local tumor recurrence by enhancing the cytoreductive capability of surgical procedures.

Evaluation of factors in high risk neonatal necrotizing enterocolitis.

Fifty-four neonates with necrotizing enterocolitis (NEC) were separated on basis of outcome. Of 35 factors compared between a high-risk and a low-risk group, only six were found to be statistically significant and useful in the development of a NEC score: number of days before beginning enteral feedings; blood pH; serum bicarbonate concentration; white blood cell differential; abdominal tenderness; and presence of portal vein gas. All laboratory values and physical and radiographic findings were from the initial presentation of NEC. Neonates with a score of 3 or more are at an increased risk of developing severe NEC with a greater than 50% mortality. The study suggests that enteral feedings should be withheld from neonates at risk of developing NEC for the first 12 days of life.