High discordance rates between sub-areolar and peri-tumoural breast lymphoscintigraphy

Targeting microbiome, drug metabolism, and drug delivery in oncology

Recent emerging scientific evidence shows a relationship between gut microbiota (GM) and immunomodulation. In the recently published "Hallmarks of Cancer", the microbiome has been reported to play a crucial role in cancer research, and perspectives for its clinical implementation to improve the effectiveness of pharmacotherapy were explored. Several studies have shown that GM can affect the outcomes of pharmacotherapy in cancer, suggesting that GM may affect anti-tumor immunity. Thus, studies on GM that analyze big data using computer-based analytical methods are required. In order to successfully deliver GM to an environment conducive to the proliferation of immune cells both within and outside the tumor microenvironment (TME), it is crucial to address a variety of challenges associated with distinct delivery methods, specifically those pertaining to oral, endoscopic, and intravenous delivery. Clinical trials are in progress to evaluate the effects of targeting GM and whether it can enhance immunity or act on the TME, thereby to improve the clinical outcomes for cancer patients.

Onco-biome in pharmacotherapy for lung cancer: a narrative review

BACKGROUND AND OBJECTIVE

The gut microbiota (GM) was recently recognized to play an important role in modulating systemic immune responses and is known to influence the effects or adverse events of immune checkpoint blockade (ICB) or carcinogenesis by crosstalk with regulators of cancer-related immunity, and this relationship is complex and multifactorial. Diversity in the gut microbiome and the abundance of specific bacterial species have been identified to be associated with better response and prognosis. Therefore, the purpose of the current interest in the gut microbiome is to enable modulation of the immune system in donor cancer patients by the administration of specific bacterial species and enabling their dominance. To understand this "terra incognita" is to uncover the role of the mechanisms underlying unknown organ functions, and this knowledge will lead to enhanced immunotherapy for lung cancer patients.

METHODS

In this article, we summarized the literature on the relationship between the microbiome and lung cancer and the potential of the microbiome as a therapeutic target.

KEY CONTENT AND FINDINGS

This article is organized into the following sections: introduction, methods, microbiota and cancer development, microbiota and lung cancer treatment, future directions, and conclusion.

CONCLUSIONS

The gut microbiome is currently becoming the hallmark of cancer research and has an established and critical role in regulating antitumor immunity and the response to ICB in patients with lung cancers.

Radio-isotope occult lesion localization (ROLL) techniques to identify the clipped node for targeted axillary dissection (TAD) in breast cancer

BACKGROUND

Breast cancer patients having neoadjuvant systemic therapy (NAST) who have a positive (clipped) lymph node (CN) at presentation must have that CN removed to assess pathologic response at later surgery. Multiple techniques for localizing the CN have been described. We describe a novel ROLL-based approach.

METHODS

Consecutive patients between 2018 and 2021, having NAST with biopsy proven positive lymph node(s), had a clip placed into the most abnormal node(s). At later surgery sentinel node and occult lesion localization (SNOLL) was performed with peritumoral radio-isotope (^99m Tc-Nanoscan) injected under ultrasound guidance. Planar and single photon emission computed tomography (SPECT-CT) images were used to identify sentinel nodes (SN) and the CN. If the CN was not a SN, then additional ^99m Tc-Nanoscan was injected directly into the CN using ultrasound (ROLL). TAD was performed using a gamma probe and intra-operative specimen radiographs to confirm excision of the CN.

RESULTS

Thirty-eight patients underwent TAD. 20/38 CNs were SNs on SPECT-CT. 17/38 CN were localized separately. 1/38 CN was not a SN and could not be identified on ultrasound. The remaining 37/38 (97.4%) of the CNs were removed intra-operatively. Pathological complete response in the axilla was identified in 18/38 cases. The CN was the only positive node in 10/20 cases. In 18/20 cases the CN contained the largest tumour deposit.

CONCLUSION

Combining SNOLL and ROLL techniques to identify the SNs and, if separate, the CN for TAD is very reliable and logistically robust, especially for units already performing peritumoral lymphoscintigraphy.

Interventional nuclear medicine: a focus on radioguided intervention and surgery

Within interventional nuclear medicine (iNM) a prominent role is allocated for the sub-discipline of radioguided surgery. Unique for this discipline is the fact that an increasing number of clinical indications (e.g. lymphatic mapping, local tumor demarcation and/or tumor receptor targeted applications) have been adopted into routine care. The clinical integration is further strengthened by technical innovations in chemistry and engineering that enhance the translational potential of radioguided procedures in iNM. Together, these features not only ensure ongoing expansion of iNM but also warrant a lasting clinical impact for the sub-discipline of radioguided surgery.

Sentinel node occult lesion localization technique for impalpable breast cancer

BACKGROUND

Mammographic screening has enabled earlier detection of breast cancer, with 25-35% of malignancies being non-palpable at diagnosis. Accurate removal and sentinel node biopsy for staging these lesions are crucial to successful management. Both these aspects are achieved by peritumoural localization with radioisotope and lymphoscintigraphy for sentinel lymph node (SN) mapping using the sentinel node and occult lesion localization (SNOLL) technique. This study reports SNOLL outcomes in a large cohort of women with non-palpable breast cancers to assess its performance and promote its logistic advantages.

METHODS

This retrospective cohort study used data from BreastSurgANZ Quality Audit supplemented with private case notes. Inclusion criteria were females >18 years, with invasive breast cancer that was asymptomatic and non-palpable at presentation, who underwent SNOLL (n = 450). Primary outcomes were proportion of successful lesion localization, proportion of patients requiring re-excision and volume of tissue excised. Secondary outcomes focused on lymphoscintigraphy success rate in detecting sentinel nodes and SN positivity rates.

RESULTS

Tumours were successfully removed with the initial SNOLL procedure in 449 cases (99.8%). The re-excision rate was 15.1% (n = 68). The mean total excision volume was 54.69 cm3 (95% CI 51.49-57.88 cm3 ; range 2.75-195.33 cm3 ), with a mean closest circumferential margin of 7.05 mm (95% CI 6.60-7.49 mm; range 0 to ≥10 mm). Lymphoscintigraphy was successful in 96.9% (n = 436) of cases. Sentinel nodes were successfully identified and removed in 99.6% (n = 448) of cases. SN positivity rate was 18.4%.

CONCLUSION

SNOLL is an efficient and effective technique for localizing non-palpable invasive breast lesions while simultaneously identifying sentinel nodes.

Internal Thoracic Lymphadenopathy in Breast Cancer

The internal thoracic (IT) nodal basin is a first-echelon drainage pathway in the breast, accounting for up to a quarter of its lymphatic drainage, primarily from the deep structures of the breast. The presence of internal thoracic node (ITN) metastases upstages the breast cancer (BC) patient to a minimum of clinical stage III disease. Medial tumors, deep tumors, young age, axillary nodal metastases, tumors of a high nuclear grade, lymphovascular invasion, and triple-negative hormone receptor status are predisposing factors for ITN metastases from primary BC. It has been observed that medial tumors carry a worse prognosis than lateral tumors when all other factors are equal, indicating that understaging of ITN has a significant impact on patient outcomes. Despite the established prognostic significance of IT adenopathy in BC, this nodal basin is not routinely staged due to the difficulty in accessing it and due to the controversy regarding its management. Since the initial ITN studies in the 1960s, improvement in imaging techniques and the availability of minimally invasive biopsy techniques have fueled renewed interest in ITNs and their clinical significance in BC. Radiologists who image and diagnose BC can offer more accurate staging assessments by consistently evaluating the IT nodal chain in the BC patient. In this article, the authors discuss current knowledge of the ITNs in BC and review ITN anatomy. The imaging appearance of pathologic ITNs using various modalities, potential mimics of IT adenopathy, and image-guided sampling techniques are described. A succinct discussion of the clinical management of ITN-positive BC and its challenges is also included. ^© RSNA, 2017.

Pre-operative sentinel lymph node localization in breast cancer with superparamagnetic iron oxide MRI: the SentiMAG Multicentre Trial imaging subprotocol

OBJECTIVE

Sentinel lymph node biopsy (SLNB) with a superparamagnetic iron oxide (SPIO) tracer was shown to be non-inferior to the standard combined technique in the SentiMAG Multicentre Trial. The MRI subprotocol of this trial aimed to develop a magnetic alternative for pre-operative lymphoscintigraphy (LS). We evaluated the feasibility of using MRI following the administration of magnetic tracer for pre-operative localization of sentinel lymph nodes (SLNs) and its potential for non-invasive identification of lymph node (LN) metastases.

METHODS

Patients with breast cancer scheduled to undergo SLNB were recruited for pre-operative LS, single photon emission CT (SPECT)-CT and SPIO MRI. T1 weighted turbo spin echo and T2 weighted gradient echo sequences were used before and after interstitial injection of magnetic tracer into the breast. SLNs on MRI were defined as LNs with signal drop and direct lymphatic drainage from the injection site. LNs showing inhomogeneous SPIO uptake were classified as metastatic. During surgery, a handheld magnetometer was used for SLNB. Blue or radioactive nodes were also excised. The number of SLNs and MR assessment of metastatic involvement were compared with surgical and histological outcomes.

RESULTS

11 patients were recruited. SPIO MRI successfully identified SLNs in 10 of 11 patients vs 11 of 11 patients with LS/SPECT-CT. One patient had metastatic involvement of four LNs, and this was identified in one node on pre-operative MRI.

CONCLUSION

SPIO MRI is a feasible technique for pre-operative localization of SLNs and, in combination with intraoperative use of a handheld magnetometer, provides an entirely radioisotope-free technique for SLNB. Further research is needed for the evaluation of MRI characterization of LN involvement using subcutaneous injection of magnetic tracer.

ADVANCES IN KNOWLEDGE

This study is the first to demonstrate that an interstitially administered magnetic tracer can be used both for pre-operative imaging and intraoperative SLNB, with equal performance to imaging and localization with radioisotopes.

The role of general nuclear medicine in breast cancer

The rising incidence of breast cancer worldwide has prompted many improvements to current care. Routine nuclear medicine is a major contributor to a full gamut of clinical studies such as early lesion detection and stratification; guiding, monitoring, and predicting response to therapy; and monitoring progression, recurrence or metastases. Developments in instrumentation such as the high-resolution dedicated breast device coupled with the diagnostic versatility of conventional cameras have reinserted nuclear medicine as a valuable tool in the broader clinical setting. This review outlines the role of general nuclear medicine, concluding that targeted radiopharmaceuticals and versatile instrumentation position nuclear medicine as a powerful modality for patients with breast cancer.

Meta-analysis of superficial versus deep injection of radioactive tracer and blue dye for lymphatic mapping and detection of sentinel lymph nodes in breast cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in early breast cancer. Currently, no consensus exists on the optimal site of injection of the radioactive tracer or blue dye.

METHODS

A systematic review and meta-analysis of studies comparing superficial and deep injections of radioactive tracer or blue dye for lymphatic mapping and SLNB was performed. The axillary and extra-axillary sentinel lymph node (SLN) identification rates obtained by lymphoscintigraphy and intraoperative SLNB were evaluated. Pooled odds ratios (ORs) and 95 per cent c.i. were estimated using fixed-effect analyses, or random-effects analyses if there was statistically significant heterogeneity (P < 0·050).

RESULTS

Thirteen studies were included in the meta-analysis. There was no significant difference between superficial and deep injections of radioactive tracer for axillary SLN identification on lymphoscintigraphy (OR 1·59, 95 per cent c.i. 0·79 to 3·17), during surgery (OR 1·27, 0·60 to 2·68) and for SLN identification using blue dye (OR 1·40, 0·83 to 2·35). The rate of extra-axillary SLN identification was significantly greater when deep rather than superficial injection was used (OR 3·00, 1·92 to 4·67). The discordance rate between superficial and deep injections ranged from 4 to 73 per cent for axillary and from 0 to 61 per cent for internal mammary node mapping.

CONCLUSION

Both superficial and deep injections of radioactive tracer and blue dye are effective for axillary SLN identification. Clinical consequences of discordance rates between the two injection techniques are unclear. Deep injections are associated with significantly greater extra-axillary SLN identification; however, this may not have a significant impact on clinical management.

Identification of the sentinel lymph node in the SNAC-1 trial

BACKGROUND

A combination of scintigraphy and a lymphotropic dye (patent blue dye (BD)) is the recommended technique to detect the sentinel lymph node (SLN) in early breast cancer. This study determined the effect of clinical factors on SLN identification in the sentinel node biopsy versus axillary clearance (SNAC) trial.

METHODS

A total of 1088 women were registered. Lymphatic mapping was performed using preoperative lymphoscintigraphy (LSG) and gamma probe (GP) combined with peritumoural injection of patent BD (971 patients) or BD alone (106 patients).

RESULTS

SLNs were identified in 1024 women (94%), localized with LSG in 779 (81.4%), and were identified by GP in 879 (91.8%). The BD identified SLNs in 890 of 1073 (82%) women. Three patients had allergic reactions. BD detected the SLNs in 141 of 178 women with negative LSG mapping and in 44 of 79 women with no hot SLNs detected intraoperatively. Age, body mass index (BMI) and tumour presentation (screen detected versus symptomatic) were significantly related to the identification of the SLN. For BD, the primary tumour location was significantly related to identification rate. The detection of blue SLN was significantly lower in women with inner quadrant tumours.

CONCLUSION

The combined technique resulted in a high identification rate. BD contributed to the identification of the SLNs in patients where LSG and GP failed to identify the sentinel node. Special attention to these techniques is needed in particular groups of patients such as those with high BMI, screen-detected primary tumours and tumour located in the inner quadrants.

A prospective validation study of sentinel lymph node biopsy in multicentric breast cancer: SMMaC trial

BACKGROUND

Multicentric breast cancer is often considered a contra-indication for sentinel lymph node (SLN) biopsy due to concerns with sensitivity and false negative rate. To assess SLN feasibility and accuracy in multicentric breast cancer, the multi-institutional SMMaC trial was conducted.

METHODS

In this study 30 patients with multicentric breast cancer and a clinically negative axilla were prospectively included. Periareolar injection of radioisotope and blue dye was administered. In all patients SLN biopsy was validated by back-up completion axillary lymph node dissection.

RESULTS

the SLN was successfully identified in 30 of 30 patients (identification rate 100%). The incidence of axillary metastases was 66.7% (20/30). The false negative rate was 0% (0/20) and the sensitivity was 100% (20/20). The negative predictive value was 100% (10/10).

CONCLUSION

SLN biopsy in multicentric breast cancer seems feasible and accurate and should therefore be considered in patients with multicentric breast cancer and clinically negative axilla.