Surprise, surprise: not knowing where your cancer started can really stress you out.This not-so-unexpected news comes from a survey of members of the Association of Oncology Social Work. Reported at the AOSW's annual meeting in May, the survey found that 81 percent of oncology social workers found cancers of unknown primary to be more distressing, significantly more distressing, or extremely distressing for their patients compared with patients who received a specific diagnosis.Some more numbers: 38 percent of social workers said the greatest challenge for CUP (that's cancer of unknown primary) patients is a general fear associated with battling something unknown. Almost just as many say patients are most troubled by the lack of a definitive therapy, while about one in five reported that patients exhibit frustration and/or anger that their cancer can't be identified.Seeing as how only about 2 percent of respondents said they felt "very well prepared" to address a patient's distress, what the survey boiled down to, according to its authors, was that social workers need better training and resources to help these patients manage the psychological impact of their cancers. Any social workers out there want to weigh in?The survey was conducted by bioTheranostics, which markets Theros CancerTYPE ID – a molecular test for determining the origin of CUP cases. We're planning to get into this more in CURE's upcoming Summer issue, which drops at the end of June. Until then, any CUP patients have advice or experiences to share?