Comparing Methods for Targeted Axillary Dissection in Breast Cancer Patients: A Nationwide, Retrospective Study

BACKGROUND

Several techniques exist for performing targeted axillary dissection (TAD) after neoadjuvant chemotherapy with the removal of the sentinel node and a marked metastatic lymph node (LN). Two-step methods include coil-marking of the metastatic LN at diagnosis and re-marking with an intraoperatively identifiable marker before surgery. Because nondetection of the marked lymph node (MLN) warrants axillary clearance and many patients achieve axillary pathological complete response (ax-pCR), the success of TAD is crucial. We compare various two-step TAD methods in a Danish national cohort.

METHODS

We included patients who received two-step TAD between January 1, 2016 and August 31, 2021. Patients were identified from the Danish Breast Cancer Group database and cross-checked with locally accessible lists. Data were extracted from the patient's medical files.

RESULTS

We included 543 patients. In 79.4%, preoperative, ultrasound-guided re-marking was possible. Nonidentification of the coil-marked LN was more likely in patients with ax-pCR. The second markers used were hook-wire, iodine seeds, or ink marking on the axillary skin. Of patients with successful secondary marking, the MLN identification rate (IR) was 91%, and the sentinel node (SN) IR was 95%. Marking with iodine seeds was significantly more successful than ink marking with an odds ratio of 5.34 (95% confidence interval 1.62-17.60). The success rate of the complete TAD with the removal of MLN and SN was 82.3%.

CONCLUSIONS

With two-step TAD, nonidentification of the coiled LN before surgery is frequent, especially in patients with ax-pCR. Despite successful remarking, the IR of the MLN at surgery is inferior to one-step TAD.

Targeted Axillary Dissection with 125I Seed Placement Before Neoadjuvant Chemotherapy in a Danish Multicenter Cohort

BACKGROUND

Targeted axillary dissection (TAD), with marking of the metastatic lymph node before neoadjuvant chemotherapy (NACT), is increasingly used for breast cancer axillary staging. In the case of axillary pathological complete response (ax-pCR), axillary lymph node clearance can be omitted. Several marking methods exist, most using re-marking before surgery. Feasibility, learning curve, and identification rate (IR) vary. Marking with 125I seed before NACT makes re-marking at surgery redundant, possibly increasing feasibility and IR. Here, TAD with 125I seed placed before NACT is evaluated in a Danish multicenter cohort.

METHODS

Patients staged with 125I TAD in Denmark between 1 January 2016 and 31 August 2021 were included. Patients were identified in radioactivity-emitting implant registries at the radiology departments and from the Danish Breast Cancer Group database. Data were extracted from patients' medical records. Information on patient/tumor characteristics, 125I seed activity, marking period, TAD success, number of sentinel nodes (SNs), the histopathological status of excised nodes, and whether the marked lymph node (MLN) was an SN were registered.

RESULTS

142 patients were included. The IR of the MLN was 99.3%, and the IR of the SLNB was 91.5%. TAD success was 91.5%. Minor challenges in marking or removal of the MLN were noted in three patients. In 72.3% of the patients, the MLN was a sentinel node. Overall, 40.8% had axillary pCR.

CONCLUSION

TAD with 125I seed marking before NACT is feasible without re-marking at surgery and with only minor surgical challenges. The IR is high. Staging with TAD spares 41% of breast cancer patients an axillary dissection.

Neuropathy and pain after breast cancer treatment: a prospective observational study

OBJECTIVES

Neurological complications including pain are common after treatment for breast cancer. This prospective study investigated the symptoms, intensity and interference of chemotherapy-induced peripheral neuro-pathy. (CIPN) in the feet and hands compared to surgery- and radiation-induced neuropathy in the breast and upper arm.

METHODS

Consecutive patients referred to surgery for breast cancer were included in a prospective study and completed a questionnaire at baseline and a follow-up questionnaire and interview after one year. CIPN was assessed with the CIPN20 questionnaire and the Michigan Neuropathy Screening Instrument questionnaire (MNSIq). Pain intensity was rated on a numeric rating scale (NRS, 0-10).

RESULTS

In total 144 patients were included, of which 73 received chemotherapy. At one-year follow-up, symptoms of polyneuropathy were more common in patients treated with chemotherapy. Tingling or numbness in the feet in those treated/not treated with chemotherapy was reported by 44 (62%) and 15 (21%), respectively. Pain was present in 22 (30%) and 10 (14%), respectively. Pain in the area of surgery was reported by 66 (46%). Although less common, pain in the feet in those treated with chemotherapy was rated as more intense and with more daily life interference than pain in the surgical area (NRS 5.5 (SD 1.9) vs. 3.1 (SD 1.9).

CONCLUSIONS

Neurological complications including pain following surgery and chemotherapy represent a burden to breast cancer survivors. In those who had received chemotherapy, pain in the feet was less common than pain in the surgical area, but pain in the feet was more intense and had a higher interference with daily life. Our study emphasizes the need for either baseline data or a control population for improved estimation of the presence and severity of CIPN and pain from questionnaires.

Impedance planimetric description of normal rectoanal motility in humans

PURPOSE

Manometry and pressure-volume measurements are commonly used to study anorectal physiology. However, the methods are limited by several sources of error. Recently, a new impedance planimetric system has been introduced in a porcine model. It allows simultaneous determination of anorectal pressures and multiple rectal luminal cross-sectional areas. This study was designed to study normal human rectoanal motility by means of impedance planimetry with multiple rectal cross-sectional areas and rectal and anal pressure.

METHODS

Twelve healthy volunteers (10 females), aged 24 to 53 years, were studied during one-hour fasting and one hour after a meal. Rectal cross-sectional areas were determined at five levels each 2 cm apart, as well as rectal and anal pressure.

RESULTS

A number of rectoanal motility patterns were observed. A total of 25 episodes with very localized cyclic rectal contractions detected at only one of five channels were observed lasting two to four minutes with a median frequency of three per minute (range, 2-6). A total of 44 episodes of cyclic rectal contractions propagating over two or more channels were detected lasting 2 to 36 minutes. Most were associated with contractions of the anal canal. A significant increase in rectal contractile activity was observed after the meal (P < 0.05). Single rectal contractions were observed in 11 subjects, and the majority were located to one channel and lasted less than 40 seconds. In two subjects who felt a need to defecate during the experiment, the cross-sectional area at all channels showed strong cyclic contractile activity and the anal pressure increased by approximately 100 percent.

CONCLUSIONS

The new rectal impedance planimetry system allows highly detailed description of rectoanal motility patterns. It has promise as a new method for description of rectoanal motility in further studies.

A new multiplex PCR for easy screening of methicillin-resistant Staphylococcus aureus SCCmec types I-V

A multiplex PCR with four primer-pairs was designed to identify the five main known SCCmec types. A clear and easily discriminated band pattern was obtained for all five types. The SCCmec type was identified for 98% of 312 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). SCCmec type IV was by far the most common SCCmec type among both hospital- and community-acquired MRSA isolates in Denmark.

Ano-rectal motility responses to pelvic, hypogastric and pudendal nerve stimulation in the Göttingen minipig

We investigated the effect of efferent stimulation of the pelvic (PN), hypogastric (HGN) and pudendal (PuN) nerves on ano-rectal motility in Göttingen minipigs using an impedance planimetry probe. Changes in the rectal cross-sectional area (CSA) at five axial positions and pressures in the rectum and anal canal were investigated simultaneously. Pelvic nerve stimulation elicited a CSA decrease in the proximal part of the rectum and a simultaneous CSA increase in its distal part. Anal pressure also decreased. Hypogastric nerve and PuN stimulation elicited an increase in anal pressure, but no rectal response. Severing the HGN produced a persistent reduction in resting anal pressure, but no change was observed when the PN and the PuN were severed. Stimulation of the distal part of all three nerves produced a persistent response. Administration of phentolamine and pancouronium eliminated the response to stimulation of the HGN and the PuN, respectively.

CONCLUSION

Rectal responses to PN stimulation vary more than previously suggested. The HGN has an excitatory effect on the internal anal sphincter, and the PuN on the external anal sphincter. However, the PuN plays no major role in maintaining basal anal pressure.

Anorectal motility responses to selective stimulation of the ventral sacral nerve roots in an experimental model

Background

Control of defaecation and continence may be lost in patients with spinal cord injury. Electrical stimulation of sacral nerve roots to promote defaecation simultaneously activates both the rectum and the external anal sphincter (EAS), and may actually obstruct defaecation. The aim of this study was to investigate whether the EAS could be blocked selectively by selective stimulation of the ventral sacral nerve roots, and whether activation of the rectum without activation of the EAS could be obtained by stimulation of the ventral sacral nerve roots.

Methods

Selective electrical stimulation was performed using anodal blocking, a tripolar cuff electrode and monophasic rectangular current pulses applied to the sacral nerve roots in nine Göttingen minipigs.

Results

Simultaneous responses in the rectum and the anal canal were observed in five animals, whereas only anal responses were noted in four. Variations in cross-sectional area and an increase in rectal pressure seemed to facilitate defaecation. Without blocking, the increase in anal canal pressure was 16–45 cmH2O. With blocking, this increase was abolished in seven and reduced to 3–6 cmH2O in two animals.

Conclusion

Selective activation of the rectum is possible using an anodal block of somatic motor fibres. This technique holds promise in further development of electro-defaecation.

New probe for the measurement of dynamic changes in the rectum

Conventional mano-volumetric techniques cannot measure changes in circumferential dimensions at several axial positions within a bowel segment. Our aims were to validate a new impedance planimetry probe for simultaneously measuring the cross-sectional area (CSA) at five axial positions in vitro and in vivo in 10 anesthetized pigs. The day-to-day coefficient of variation (CV) for CSA measured by the probe in cylindrical tubes of known diameter was 0.8-9.5%. The mean from actual diameter deviation ranged from 2.3 to 6.7%. In a conical tube the day-to-day CV was 2.3-8% and mean percentage deviation -2.8 to 1.0. Interposed narrowing sections caused a total CV of 7-13%. In vivo studies revealed variations in CSA, associated with expulsion of flatus. It is concluded that impedance planimetry allows simultaneous measurement of CSA at several levels within the rectum. In vitro validity was acceptable and alterations in lumen diameter were identified in vivo.

Bladder and urethral responses to pelvic nerve stimulation in the pig

OBJECTIVE

The aim of our study of the pig was to investigate the responses of smooth muscle of the bladder and the urethral sphincter to preganglionic parasympathetic stimulation, and to assess the effect on the lower urinary tract of IV administration of alpha,beta-methylene-ATP.

MATERIALS AND METHODS

In seven anaesthetised female pigs, the responses to repeated 20 s pelvic nerve stimulations before and after IV administration of 0.02 mg/kg alpha-beta-methylene-ATP, and the responses to the drug itself, were recorded in the bladder and the urethra separately.

RESULTS

In the urethral high-pressure zone, pre-stimulation pressure was a mean of 61+/-11 cmH2O. During pelvic nerve stimulation, urethral pressure declined by 48+/-9 cmH2O, while the bladder pressure increased to 30+/-18 cmH2O. The rate of pressure changes during the first 3 s of stimulation (initiation of voiding) was larger in the urethra than in the bladder (urethral pressure decrease: 13.0+/-3.1 cmH2O/s, bladder pressure increase: 3.2+/-2.5 cmH2O/s). Administration of alpha,beta-methylene-ATP was followed by a significant but temporary enlargement in the bladder response to pelvic nerve stimulation to 36+/-20 cmH2O, p = 0.028, n = 7, but no change in urethral response.

CONCLUSIONS

At least 80% of the urethral pre-stimulation pressure was exerted by the smooth muscle. The synergic activation of the detrusor and the urethral smooth muscle in response to preganglionic parasympathetic nerve stimulation was controlled by the peripheral nerves or by the neuromuscular transmission. Administration of alpha,beta-methylene-ATP increased the bladder response to pelvic nerve stimulation without changing the urethral response.