1. FLOT versus CROSS: I would favour perioperative FLOT followed by surgery for this Siewert II GEJ adenocarcinoma. ESOPEC demonstrated better overall and progression-free survival with FLOT compared with CROSS in oesophageal adenocarcinoma. FLOT also provides stronger systemic therapy for a cT3N1 tumour with significant risk of distant relapse. CROSS remains a reasonable option where radiotherapy is readily available, but in this patient, who is self-funding treatment, the repeated daily radiotherapy visits, travel and potential treatment interruptions are important practical considerations. I would therefore optimize his hydration and nutrition first, then proceed with FLOT and restaging before surgery. I would not recommend immediate surgery simply for relief of obstruction if nutritional support and decompression can be achieved. I would not, however, describe FLOT as definitively equivalent to CROSS followed by nivolumab, since these strategies have not been directly compared.
2. Baseline neuropathy: I would document the baseline neuropathy using CTCAE, including its severity and effect on function. Grade 1 neuropathy without functional impairment can generally be monitored while continuing oxaliplatin. With persistent grade 2 or functionally significant neuropathy, I would consider dose reduction or treatment delay. More severe neuropathy would warrant withholding or discontinuing oxaliplatin according to the treatment protocol. The decision should be based on severity and functional impact, rather than automatically removing oxaliplatin.
3. Monitoring adverse events: Before treatment, I would document ECOG status, weight/nutritional status, hydration, FBC, renal and liver function, electrolytes, dysphagia, pain and baseline neuropathy. Before each cycle, I would assess neuropathy, mucositis, nausea/vomiting, diarrhoea, fatigue, appetite, weight, dysphagia, pain, infection and functional status, together with appropriate laboratory tests. Between visits, a simple patient toxicity diary can record fever, vomiting, stool frequency, oral intake, pain and neuropathy. Telephone/WhatsApp follow-up calls or messages by the oncology team would be useful, with urgent review for fever, dehydration, persistent vomiting/diarrhoea, bleeding or rapidly worsening neuropathy.
4. Three-week biomarker waiting period: I would not delay cytotoxic treatment for three weeks solely while waiting for HER2, MMR and PD-L1 results, provided the patient has been adequately stabilized and is fit to receive chemotherapy. The three weeks should instead be used to correct dehydration and electrolytes, provide nutritional support, address the obstruction, document baseline toxicity and expedite the biomarker results. Once clinically fit, FLOT can be commenced while awaiting the results. Biomarker-directed therapy can then be considered when the results are available.
Overall: I would favour perioperative FLOT, after nutritional optimization, with individualized oxaliplatin modification, structured toxicity monitoring and no unnecessary three-week delay while awaiting biomarkers.