Lung Nodules on PET Scan

My mom has parotid cancer removed in the Spring 2008 (Myoepithelial carcinoma- intermediate grade, 1.5 CM).  14 nodes were removed, all negative for tumor.  Post surgery, she was treated with radiation as they couldn't get clear margins as the tumor was sitting on the nerves which were spared.

She was just disgnosed with breast cancer (moderately differientated invasive ductal carcinoma, 1.2 CM).  She had the same cancer nearly 20 years ago in the same breast, treated by lumpectomy and radiation, lymphnodes were clear.

In the work up prior to her mastectomy lscheduled for ater this month, she had a bone scan--clear and Chest CT scan which showed new lung nodules (and old ones that have remained stable).  PET showed an 8mm nodule at the top of the trachea in the right lung (I think, don't have the report in front of me).  Also, it showed a 5mm and a 6mm nodule in the bottom of the left lung.  From what I understand second hand, PET did not show lymph activity.

Questions:

1) DR said that these are too small for needle biopsy so we will monitor them for now.  Does this sound right?

2) Is it possible that these lung nodules are metastised from the parotid and have somehow skipped the lymph nodes?  (The radiologist's report said they do not think that it is from the breast, but they are not sure).  

3) The oncologist is having her start Arimidex now on the off chance that the lung nodules have come from the breast (ER/PR+, Her2 - tumor) and will rescan in approx 45 days to see if they have shrunk.  Assuming they don't, if cancerous, how large can these nodules get in this time frame?

I understand this isn't a replacement for a consult with her DRs, but I am just trying to gather some info for my own knowledge/understanding as we are all obviously a bit shell shocked.

[Questions12345]

Got my hands on the report as it relates to my questions above.  Thanks so much--

"An 8 mm hypermetabolic nodule (SUV max 2.8) is seen deep in the right hilar region." Review of an earlier CT scan of chest from March 2008 shows no nodule.

"Two additional small nodules are seen at the left lung base.  These measure 5-6 mm in size and are barely perceptible on the PET CT Scan, but are probably below the resolution for PET evaluation."

[HeinrikMD]

Hi,

On hitting the nodule: the size of course has a lot to do with it. One algorithm included only those at least 8 mm, so the mediastinal node may qualify. The second issue is the location, whether it is technically within the range of the instrument (usually a needle or a brush).

On the parotid being the primary: Yes, however a size of 1.5 cm doesn’t usually have any problems after removing it. The same however can be said for the breast cancer.

On the delay allowing for cancer to grow: This of course depends on its behavior. There are reports however, from patients who had delays in radiation therapy, and the growth can be 50% or more. Bear in mind though, that these are small lesions, so a doubling in size may not even have any specific symptoms.

Perhaps you need to re-evaluate the goals in her case. The doctors have given her a clear shot at cure by going through with the mastectomy as the nodules do not seem to be related. Best case scenario, the nodules are not malignant, so all that is needed would be observation. Worst case scenario, they are malignant and this is already disseminated disease. In such a case however, it may be more prudent to give medicine as treatment first  (such as the Arimidex) and if there is a proven response, you may want to talk about the merits of performing another surgery or radiation (whether she is a candidate for such procedures). Stay positive.  

[Questions12345]

Thank you so much for your detailed respnse.  A few follow-up items if I may:

1)  Any chance this could by some fluke (three primary cancers in one year) be a primary cancer?

2) Given the size of the 1 nodule and the associated SUV, is there any hope at all that these are not malignant?

3) Assuming this is cancer and secondary, is there hope for a "cure" such as we had when we removed the parotid tumor and will have mastectomy in a week and a half?

4) If there isn't nodal involvement (e.g. with the parotid in this case), how does the cancer spread?  (blood?)

PS--I think we are doing what you suggest in your comments.  She's started the Arimidex already.  And, she has a mastectomy scheduled in a week and a half.  Then we will recan the chest in approx 45 days and go from there.  In the meantime, they are meeting with her head and neck surgeon this coming week to try to figure out where to go from here in terms of assembling a team to supervise her overall care.

Thanks so much for your thoughtful response above.  It is much appreciated as you can imagine, this is a tough time for us.

[HeinrikMD]

Hi,

It is possible that the nodules represent multiple primary cancers, but it is more probable that they are not. The presence of multiple nodules without a single dominant mass tends to speak of disease coming from outside the lung.  For certain cancers, such as colon and melanoma, there are certain patients who can be offered to have the nodules removed, and such a plan can lead to prolonged survival. For the parotid or for breast cancer however, this isn’t routinely done.

The PET scan doesn’t have a signature that is really specific for cancer. There are infections and inflammatory disease that can have the same signature as cancer. IF there are risks for these other conditions, then the odds that they are not malignant become higher.

Metastases into the lung may be due to blood borne cancer, so yes, they may have traveled via the blood stream. For breast cancer, it is estimated that at 1 cm, the risk for distant metastasis starts to rise due to the requirement of the mass for its blood supply, which feeds the cancer and secondarily can serve as an avenue for dissemination.

[Questions12345]

Thanks again, and sorry, but one follow up question.

What are the risk factors for infection/inflammatory disease?  She has been a smoker until recently and I wouldn't be surprised if her immune system is compromised post parotid surgery/radiation.  She's lost about 40 lbs in the last 6 months, and was small to begin with.

Thanks again.  Consult with her head and neck surgeon is this week so hopefully we'll know more then.

[HeinrikMD]

Hi,

Some of the things to consider would be tuberculosis, in which exposure is more common in some parts of the world more than others. Hence the risk is a question of exposure. Sarcoidosis is more common in the 3rd and 4th decade of life, the cause is unknown, but it is believed to be an abnormal immune-related disease. Sarcoidosis can involve other organs including the skin, so some of the other manifestations may be sought. Inflammatory disease such as rheumatoid arthritis involves primarily joints, so an examination of the hands would be important. There are some benign nodules that are normal tissue in an aberrant location. These can only be known definitively when a biopsy is performed.

[Questions12345]

Hi, I am back nearly 2 months later post mastectomy and follow up CT Scan.

Mom's been on Arimidex for this 2 month period as well.  The 7mm nodule has increased to 12 mm.  There are now more nodules, a total of 6 on the left and 3 on the right.  We are waiting to see if the DRs can get in and biopsy.  

Any initial thoughts?  Thanks so much for any thoughts.

[Questions12345]

Sorry, forgot to mention the report also notes "no pleural effusions" and "no lymphadenopathy."