Welcome to the club nobody wants to be a part of. I'm sorry to hear your situation. I too have SS in my left lung, in a lymph node right there, as well as in the plural lining of my lung, but on the inside. I started my treatment with the insertion of a port, which you probably already have by now. In my case, the port is on the right side. Mine does stick out, but I'm not really sure how noticeable it really is now that the stitches have all healed (I had mine installed in August). Once it heals completely, you can't even tell it's there and it will be your best friend.
I started chemo right away and did six rounds of doxorubicin, ifosimide, and mesna. I spend five days in the hospital for each chemo treatment. The port is ideal because, as my doctor told me, doxo is a horrible chemo and they would prefer not to push that through a smaller vein as eventually it will damage the vein. The port allows the chemo to go through a much larger vein, thus causing less damage. It's also horribly convenient for all the blood draws that happen when you're in the hospital, as there is no reason to poke you, they can draw blood through your port. Always have the card they give you that comes with your port because if you need a CT scan with contrast, if you can show your card that identifies your port, they can also push the contrast through your port instead of having to get an IV. I know with all the blood testing I've had to do and the chemo I've had, good veins get harder to find, thus the port being your best friend!
As far as the effectiveness of the chemo, a doctor explained it to me this way. Every body responds differently, every tumor differently. After six rounds, my tumors shrunk on average 50-60%. The purpose of chemo was not to cure my cancer, but to shrink the tumors thus allowing clearer margins for surgery. Chemo does kill SS cells, the problem is tumors can be so large that our bodies can't possibly consume enough chemo to effectively kill the whole tumor. The smaller the tumor, the more successful and the most likely it will respond, in SOME cases. Again, not all tumors respond the same.
I have since had my entire left lung,the plural lining, the lymph nodes and part of my diaphram removed, which in essence should have removed all my known cancer. I have since had some complications (infections) since surgery that I'm currently recovering from, but once I do, I will have a couple more rounds of chemo in hopes of killing any random cancer cells that may be floating around. I'm hopeful for success now that I understand that A) my tumors did respond to chemo and B) it's very likely chemo can kill smaller cancer cells.
I too an not a candidate for radiation due to where our cancer is. Surgery may be an option, but it's a big surgery and they'll only do something like that if they consider it life saving, which in my case it is. Conclusively, they have also removed the pericardium that surrounds the heart because of fluid retention due to this infection I'm fighting.
I think that while we have a horrible cancer, there is hope. There are lots of options out there that didn't exist before, so don't let the statistics on the internet scare you. There is a lot to learn about chemo that you're about to go through, So many of us here have been through all those things and can answer any questions that come up. Trust me, I learned a new side effect practically at every round of chemo that I wish I knew going into it. Best of luck, I hope you were able to enjoy prom.