<s>[INST] Hello doctor, My father was diagnosed with adenocarcinoma of the esophagus six months back, stage II to III with a few malignant lymph nodes. He underwent surgery which was a success. He is taking chemotherapy right now, which is supposed to eliminate the malignant lymph nodes, which have spread to other parts of his body. He has his fourth dose of chemotherapy planned for next week. However, one of the lymph nodes located on the left side right under his neck is constantly growing, so doctors are planning to change the type of chemo after the next PET scan. I have a few questions regarding the condition of my father. The first one is does lymph node growth indicate that the chemo is not working, and the nodes are actually getting bigger? Or it may be something else (like the creation of cysts or capsules around the node)? I know we cannot be sure what is happening until the PET scan, but we would like to know this information so we know what to expect. The second question is when chemotherapy is not working, is it standard to actually try more types before finding one that starts working? I know these are not easy questions to answer, but my father is very anxious and knowing as much as possible would help him immensely with his physical condition. [/INST] Hello. So, I have gone through your queries. I would like to know a few details which will help me in answering your questions. So before surgery what was his stage? What did baseline CT or PET (whichever was done) showed? Did he receive any chemotherapy prior to surgery? Or was the decision taken to go ahead with surgery? What chemotherapy is he receiving? What surgery did he have and what was post-surgery histopathology report? His age, general fitness, and any other illness? Now coming to your questions. LN (lymph node) growing during chemotherapy means usually disease is not responding in 95 % cases. Rarely there are nonmalignant causes (usually infective) which can also cause LN enlargement. So depending on the clinical picture, risk, and possibility of other etiology and imaging, the decision is taken to change treatment. Your physician sometimes may want to be sure that the LN is due to disease only then he can sometimes suggest FNAC or biopsy of LN. When one chemotherapy is not working, we go to the second line. Usually, idea is to start chemotherapy which is standard and which patient can tolerate. So it is not like we try different choices before finding the right one. We start with a standard one and if the patient is not responding we go to the second line. If first-line treatment is not working the chances of next line working also goes down. Also, second line options may have more side effects. This decision is taken usually with patient and physician preference. </s>