SEER Inquiry System - Question 20220048 Details

The SEER Manual states that the Other Therapy data item identifies treatments given that cannot be classified as surgery, radiation, systemic therapy, or ancillary treatment; and the instructions for code 2, Other-Experimental, say to assign this for any experimental or newly developed treatment, such as a clinical trial, that differs greatly from proven types of cancer therapy.  Does this mean that only unclassifiable treatments should be coded in Other Therapy, even if given as part of a clinical trial? 

For example, if a patient is given a drug as part of a trial that is categorized in SEER*Rx as immunotherapy, should it be assigned both Immunotherapy (NAACCR #1410) code 1 and Other Therapy code 2, or only coded in Immunotherapy since it is classified as such?  How should a clinical trial drug be coded if it has a treatment classification in SEER*Rx, but the type of cancer being treated is not listed under the Primary Site or Remarks sections as being FDA approved?  A real case scenario is atezolizumab given for colon cancer as part of a trial; this drug's category is Immunotherapy in SEER*Rx but colon is not listed under Primary Sites or in the Remarks detailing FDA approvals.