Histopathological Response to Neoadjuvant Chemotherapy in Patients With Enneking Stage II Conventional Osteosarcoma of Extremities: A Retrospective-Single Institution Study in Vietnam.

BACKGROUND: The standard treatment for localized osteosarcoma is neoadjuvant chemotherapy before surgery, followed by adjuvant chemotherapy. Our aim was to report the rate of histopathological response to neoadjuvant chemotherapy for the treatment of extremity osteosarcoma in Vietnam. METHODS: We performed a retrospective study of stage II conventional osteosarcoma patients under 40 years-old who received MAP regimen as neoadjuvant chemotherapy at the Vietnam National Cancer Hospital between June 2019 and June 2022. Histopathological response was evaluated using the Huvos grading system, in which a good histopathological response was defined as a necrotic rate of 90% or more. RESULTS: Thirty-five eligible patients were included in the study. Male patients accounted for 65.7%, with a median age of 16 years (range, 8-38 years). Of the 35 cases, 31 were reported as stage IIB (88.6%). The femur and tibia were the most common sites in our study, accounting for 51.4% and 34.3%, respectively. The most common pathologic subtype was osteoblastic osteosarcoma (68.6%), followed by chondroblastic subtype (20%). After two cycles of MAP-regimen neoadjuvant chemotherapy, 28 of 35 patients (80%) underwent limb-sparing surgery. A good histopathological response was observed in 18 of 35 patients (51.4%). There were significant correlations between the duration of symptoms (P = 0.016), LDH (P = 0.001) serum levels at initial presentation, and ALP (P = 0.043) serum levels at initial presentation with histopathological response. CONCLUSION: This retrospective study suggests a possible association between symptom duration, pre-treatment LDH levels, and pre-treatment ALP levels with histopathological response rates. Additional clinical investigations with long-term follow-up are needed to investigate survival outcomes in the Asian population.

Rare T263P epidermal growth factor receptor extracellular domain mutation of advanced non-small cell lung cancer in a Vietnamese male patient.

T263P mutation is one of the rare EGFR mutations located on chromosome 7p11.2, which is a change in amino acid residue at position 263 of the epidermal growth factor receptor protein, where L-threonine has been replaced by L-proline. This missense mutation in the extracellular EGFR domain is not well-known in lung cancer. In this study, we first report a patient with advanced lung adenocarcinoma harbouring only a rare T263P EGFR mutation who benefited from first-line afatinib therapy in Vietnam. The patient achieved a partial response with a time-to-treatment failure of 5 months. The patient subsequently received several chemotherapy regimens as the disease progressed, with overall survival of 17 months. Non-small cell lung cancer with a rare T263P EGFR mutation responds to afatinib but has a poor prognosis. Further studies are needed to determine the efficacy of targeted therapies in this specific population.

PD-L1-negative non-small cell lung cancer harbouring a rare BRAF mutation with successful treatment of first-line pembrolizumab plus chemotherapy: A case report and review the literature.

BRAF mutations are uncommon in non-small cell lung cancer (NSCLC), accounting for less than 5% of all NSCLC cases. The utilization of targeted therapies in non-V600E BRAF mutant NSCLC is considered controversial, although non-V600E genotype is reported in ~50% of all BRAF mutant patients. We document the case of a 63-year-old patient with NSCLC harbouring a rare BRAF E501Q mutation, who had prolonged response to immunotherapy combined with chemotherapy in Vietnam. The patient was diagnosed with metastatic PD-L1-negative lung adenocarcinoma and received pembrolizumab plus chemotherapy as first-line treatment. After completing 35 cycles of pembrolizumab and pemetrexed, his disease has remained stable during the treatment-free follow-up period, and he is alive 38 months after treatment initiation at the latest follow-up. Immune-based therapy is an appropriate option for lung adenocarcinoma with rare non-V600E BRAF mutation. Further clinical studies are necessary to determine the effectiveness of using immune-based therapy in this specific population.

Pathological Complete Response with Neoadjuvant Trastuzumab Combined with Chemotherapy in HER2 Positive Breast Cancer: A Single Institution Retrospective Analysis from Vietnam.

PURPOSE: Neoadjuvant regimens containing trastuzumab and chemotherapy were widely used in human epidermal growth factor 2 (HER2) positive breast cancer patients. In this article, we report complete pathological response (pCR) rates from a single institution in Vietnam. PATIENTS AND METHODS: Medical records of HER2 positive breast cancer patients who received neoadjuvant treatment with trastuzumab combined with chemotherapy were reviewed. Information on patient demographics, breast cancer stage, pathology reports, surgical data, and treatment regimens were collected. Pathological response was evaluated using Chevallier's criteria, in which complete pathological response was defined as yT0yN0 or yTisN0. RESULTS: Thirty-nine eligible breast cancer patients treated with chemo-trastuzumab combined regimens in a neoadjuvant setting at Vietnam National Cancer Hospital were included in the analysis. Median age was 47 (range 32-72 years). Of these 39 patients, 5 (12.8%) were at stage II and 34 (87.2%) were at stage III. Median tumor size was 5.8 cm. There were 22 (56.4%) and 17 (43.6%) patients who had hormone receptor (HR) negative and positive diseases, respectively. Pathological complete response in the breast was demonstrated in 30 out of 39 (76.9%) patients. Of 35 patients with lymph nodal involvement, axillary pCR occurred in 25 (71.4%) patients. Total pathological complete response (tpCR) was achieved in 25 (64.1%) of the evaluated patients. There was no significant association between pathological response rates and age, tumor grade, hormone receptor status, and Ki-67 expression. CONCLUSION: Neoadjuvant treatment with trastuzumab and chemotherapy combined in patients with HER2 positive breast cancer yielded a pathological complete response rate of 64.1%.