Comprehensive molecular and clinical insights into non-small cell lung cancer transformation to small cell lung cancer with an illustrative case report

Histologic transformation to small cell lung cancer (tSCLC) is a rare but increasingly recognised mechanism of acquired resistance to tyrosine kinase inhibitors (TKI) in patients with epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC). Beyond its acknowledged role in TKI resistance, histologic transformation to SCLC might be an important, yet under-recognised, mechanism of resistance in NSCLC treated with immunotherapy. Our review identified 32 studies that investigated tSCLC development in patients with EGFR-mutated NSCLC treated with TKI therapy and 16 case reports of patients treated with immunotherapy. It revealed the rarity of tSCLC, with a predominance of EGFR exon 19 mutations and limited therapeutic options and outcomes. Across all analysed studies in EGFR-mutated NSCLC treated with TKI therapy, the median time to tSCLC development was ∼17 months, with a median overall survival of 10 months. Histologic transformation of EGFR-mutated NSCLC to SCLC is a rare, but challenging clinical problem with a poor prognosis. A small number of documented cases of tSCLC after immunotherapy highlight the need for rebiopsies at progression to diagnose this potential resistance mechanism. Further research is needed to better understand the mechanisms underlying this phenomenon and to develop more effective treatment strategies for patients with tSCLC.

Breast lump as the initial presentation of metastatic uterine leiomyosarcoma: a case report and comprehensive literature review

Uterine leiomyosarcoma (uLMS) is a rare but aggressive cancer with a high metastatic potential and an unfavorable prognosis. A 54-year-old woman with a history of uterine fibroids clinically presented with a painless, palpable left breast mass measuring 20 mm. A core biopsy of the breast mass demonstrated a cellular spindle cell neoplasm (a potentially malignant smooth muscle neoplasm; B4). A wide local breast-mass excision was performed, revealing grade-2 leiomyosarcoma. A re-review of the uterine fibroids revealed that the largest one (200 × 130 mm), initially diagnosed as symplastic leiomyoma, was morphologically identical to the breast lesion. Additional diagnostic work-up revealed multiple liver and pulmonary metastases with a suspected metastatic sclerotic lesion in the L3 projection. The patient was subsequently treated with chemotherapy protocol for metastatic uLMS. The latest follow-up in September 2023 confirmed stable disease. This case highlights the importance of considering unusual metastatic patterns when evaluating breast masses, particularly in patients with a history of non-specific uterine conditions. Comprehensive diagnostic work-up, including imaging and histopathologic examinations, is crucial for an accurate diagnosis of uLMS and appropriate treatment selection. Further studies are needed to better understand the underlying mechanisms and optimal management strategies for metastatic uLMS.

Comprehensive genomic profiling of a metastatic small cell lung carcinoma with a complete and long-term response to atezolizumab: A case report

Small cell lung cancer (SCLC) is a highly aggressive malignancy with a poor outcome. We present the case of a 57-year-old male patient with extensive-stage (ES-SCLC) treated with chemotherapy and atezolizumab. A complete response was achieved with a long remission of ∼three years. Comprehensive genomic profiling (CGP) of the tumor revealed high tumor mutation burden (13 mutations/Mb) and mutations of TP53, RB1 and ERCC4 genes. This case study confirms that a complete response to chemoimmunotherapy may be achieved in the case of ES-SCLC. It further provides the additional value of CGP and predictive testing in the management of ES-SCLC.

Evaluating risk of hospitalization with G-CSF use in real-world oncology practice

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Background: Limited published data exist on how granulocyte colony-stimulating factor (G-CSF) treatment patterns affect risk of neutropenia-related hospitalizations. This study examines prophylactic vs. delayed use of G-CSF and compares the effectiveness of prophylaxis with filgrastim (FIL) vs. pegfilgrastim (PEG). Methods: A retrospective analysis of administrative claims from U.S. commercial health plans identified adult patients with non-Hodgkin's lymphoma, breast, or lung cancer, treated with chemotherapy between July 2004 and January 2008. For these patients, the first course of chemotherapy and each unique cycle with use of G-CSF (FIL or PEG) was identified and designated ‘prophylaxis’ if used within the first 5 days of each cycle, or ‘delayed', if after day 5. The risk of neutropenia-related hospitalization was then evaluated on a cycle basis. A generalized estimating equation (GEE) was used to adjust for baseline demographics and clinical characteristics. Results: Among 5,571 patient-cycles identified: 87.4% were prophylactic and 12.6% were delayed G-CSF. PEG use was primarily prophylactic (93.6%) in contrast to use of FIL which was delayed in 62.5% of patient-cycles. The rate of neutropenic hospitalization was 1.2% for prophylaxis (n=59) and 3.7% for delayed G-CSF (n=26) (P < 0.001). Among prophylactic patient-cycles, the neutropenic hospitalization rate was lower with PEG than FIL (1.1% (n=51) vs. 3.5% (n=8), p = 0.001). Multivariate analyses using GEE model showed consistent trends (Table). Conclusions: Prophylactic G-CSF use was associated with lower neutropenic hospitalization risk than delayed use. Among prophylactic use in real-world oncology practice, PEG was associated with about a two-thirds lower risk of neutropenic hospitalization compared with FIL.

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[Table: see text]

Risk of mortality in patients with cancer experiencing febrile neutropenia

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Background: Febrile neutropenia (FN) is a serious and potentially life-threatening condition that may develop in patients with cancer treated with chemotherapy. The risk of mortality from FN is not well characterized in clinical practice. Methods: Patients with cancer receiving chemotherapy in clinical practice were identified from the HealthCore Integrated Research Database, a geographically diverse spectrum of fully adjudicated longitudinal claims data from 13 health plans with over 20 million US lives. Patient enrollment data, full medical care, prescription drug use and mortality (confirmed using the National Death Index) were examined for each eligible patient. Patients experiencing FN were compared to propensity score-matched patients not experiencing FN within tumor types of Non-Hodgkin lymphoma (NHL), breast, lung, colorectal and ovarian cancer. Study endpoints included overall mortality (anytime during follow-up) and early mortality (during a chemotherapy course). Logistic regression was used to calculate odds ratios (OR), adjusted for demographics, comorbidities, and other covariates. Results: Matched FN and control groups each contained 5,176 patients. Crude incidence rates of overall and early mortality were significantly higher for patients in FN group compared to controls for all tumor types [7.9/1000 person-months (PM) (95% confidence interval [CI] = 7.3, 8.5) vs. 5.6/1000 PM (CI = 5.1, 6.1), P < 0.0001; and 3.4/1000 PM (CI = 3.1, 3.9) vs. 2.4/1000 PM (CI = 2.1, 2.8), P = 0.0001, respectively]. Within tumor strata, lung cancer had the highest mortality rates and breast cancer had the lowest; NHL had the largest magnitude of difference between FN and controls (overall mortality: 7.2/1000 PM [CI = 5.3, 9.7] and 3.3/1000 PM [CI = 2.1, 5.1], P = 0.0035; early mortality: 3.0/1000 PM [CI = 1.8, 4.8] and 1.5/1000 PM [CI = 0.8, 3.0], P = 0.1103). Logistic regression demonstrated a significant increase in risk of overall and early mortality in patients with FN compared to controls (OR = 1.77 [1.53, 2.05] and OR = 1.73 [1.41, 2.11]) respectively. Conclusions: The crude and adjusted risk of mortality in patients experiencing FN is almost two-fold higher than comparably matched patients without FN. Prevention of FN is of high importance and should be carefully considered in clinical practice.

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