A Four-Arm Randomized Clinical Trial of Topical Pain Control for Sentinel Node Radiotracer Injections in Patients with Breast Cancer.

BACKGROUND: Radioactive tracer injections for breast cancer sentinel lymph node mapping can be painful. In this randomized trial, we compared four approaches to topical pain control for radiotracer injections. METHODS: Breast cancer patients were randomized (9 April 2021-8 May 2022) to receive the institutional standard of ice prior to injection (n = 44), or one of three treatments: ice plus a vibrating distraction device (Buzzy®; n = 39), 4% lidocaine patch (n = 44), or 4% lidocaine patch plus ice plus Buzzy® (n = 40). Patients completed the Wong-Baker FACES® pain score (primary outcome) and a satisfaction with pain control received scale (secondary). Nuclear medicine technologists (n = 8) rated perceived pain control and ease of administration for each patient. At study conclusion, technologists rank-ordered treatments. Data were analyzed as intention-to-treat. Wilcoxon rank-sum tests were used to compare pain scores of control versus pooled treatment arms (primary) and then control to each treatment arm individually (secondary). RESULTS: There were no differences in pain scores between the control and treatment groups, both pooled and individually. Eighty-five percent of patients were 'satisfied/very satisfied' with treatment received, with no differences between groups. No differences in providers' perceptions of pain were observed, although providers perceived treatments involving Buzzy© more difficult to administer (p < 0.001). Providers rated lidocaine patch as the easiest, with ice being second. CONCLUSION: In this randomized trial, no differences in patient-reported pain or satisfaction with treatment was observed between ice and other topical treatments. Providers found treatments using Buzzy® more difficult to administer. Given patient satisfaction and ease of administration, ice is a reasonable standard.

Clinical Trials That Have Informed the Modern Management of Breast Cancer.

Randomized controlled trials have informed the historical evolution of breast cancer management, distilling operative and nonoperative treatments to achieve disease control and improve survival while maximizing quality of life and minimizing complications. The authors describe landmark trials investigating and influencing the following aspects of breast cancer care: extent of breast surgery; axillary management; neoadjuvant and adjuvant therapies; and selection of chemotherapy versus endocrine therapy via application of genomic assays.

Sarcomas of the Breast.

Sarcoma of the breast is extremely rare and differs from epithelial breast carcinomas in staging and treatment. Diagnostic workup includes breast imaging and core biopsy as in breast epithelial carcinoma. Surgical management is often wide local excision in the form of breast conservation if possible for primary breast sarcoma or total mastectomy. Radiation-associated breast angiosarcomas often require total mastectomy with radical excision of skin. Breast sarcomas have a hematogenous spread so lymph node evaluation is not a part of treatment or staging. Local recurrence rates are high; prognosis remains poor despite on-going advances in the treatment of epithelial breast carcinoma.

Management of the clinically node-negative axilla in primary and locally recurrent breast cancer.

For patients with primary breast cancer, nodal status remains a key determinant for overall prognosis. Sentinel lymph node biopsy (SLNB) has become standard care for staging patients who have clinically node-negative disease. However, a new dilemma has arisen: how to manage the clinically negative axilla in patients with ipsilateral breast tumor recurrences (IBTRs). Are outcomes in these patients improved with repeat SLNB? Although observational studies suggest SLNB is feasible in patients with IBTR and a clinically node-negative axilla, the overall impact on morality and local recurrence is not yet known as no randomized trials have addressed this issue.

In vitro sarcoma cells release a lipophilic substance that activates the pain transduction system via TRPV1.

BACKGROUND: Despite success in treating many forms of cancer, pain associated with malignancy remains a serious clinical issue with a poorly understood etiology. This study determined if certain sarcoma cell lines produced a soluble factor that activates the TRPV1 ion channel expressed on nociceptive sensory neurons, thereby activating a major pain transduction system. MATERIALS AND METHODS: Trigeminal ganglia were harvested from rats and cultured. A rhabdomyosarcoma (CRL1598) and osteosarcoma (CRL 1543) cell line were grown to 75% confluency. Conditioned media (CM) was collected after 24 h of exposure and subjected to reverse phase chromatography. Neuronal activation in the presence of CM was measured using iCGRP RIA and calcium imaging after treatment with vehicle or I-RTX, a potent TRPV1 antagonist. Data were analyzed by ANOVA/Bonferroni or t test. RESULTS: The rhabdomyosarcoma CM produced a 4-fold increase in iCGRP release compared with control media (P < 0.001). The osteosarcoma cell line CM produced a 7-fold increase in iCGRP release compared with control media (P < 0.001). This evoked iCGRP release was via TRPV1 activation since the effect was blocked by the antagonist I-RTX. The application of rhabdomyosarcoma CM produced about a 4-fold increase in [Ca(2+)]I levels (P < 0.001), and this effect was blocked by pretreatment with the TRPV1 antagonist, I-RTX. CONCLUSIONS: We have shown that certain sarcoma cell lines produce a soluble, lipophilic factor that activates the peripheral nociceptor transduction system via TRPV1 activation, thereby contributing to cancer pain. Further investigations are needed to develop tumor-specific analgesics that do not produce unwanted or harmful side-effects.

alpha7 nicotinic receptor gene promoter polymorphisms in inbred mice affect expression in a cell type-specific fashion.

Inbred mouse strains display significant differences in their levels of brain alpha7 nicotinic acetylcholine receptor (alpha7 nAChR) expression, as measured by binding of the alpha7-selective antagonist alpha-bungarotoxin. Variations in alpha-bungarotoxin binding have been shown to correlate with an animal's sensitivity to nicotine-induced seizures and sensory gating. In two inbred mouse strains, C3H/2Ibg (C3H) and DBA/2Ibg (DBA/2), the inter-strain binding differences are linked to a restriction length polymorphism in the alpha7 nAChR gene, Chrna7. Despite this finding, the molecular mechanism(s) through which genetic variability in Chrna7 may contribute to alpha7 nAChR expression differences remains unknown. However, studies of the human alpha7 nAChR gene (CHRNA7) previously have demonstrated that CHRNA7 promoter polymorphisms are associated with differences in promoter activity as well as differences in sensory processing. In the present study, a 947-base pair region of the Chrna7 promoter was cloned from both the C3H and DBA/2 inbred mouse strains in an attempt to identify polymorphisms that may underlie alpha7 nAChR differential expression. Sequence analysis of these fragments identified 14 single nucleotide polymorphisms (SNPs). A combination of two of these SNPs affects promoter activity in an in vitro luciferase reporter assay. These results suggest a mechanism through which the Chrna7 promoter genotype may influence interstrain variations in alpha7 nAChR expression.