You can find handful of information here http://apos-society.org/. Two kinds of psychotherapy are well studied mindfulness-based therapy, meaning-centered psychotherapy (J Consult Clin Psychol. 2012 Dec;80(6):1007-20. doi: 10.1037/a0028329; Curr Psychiatry Rep. 2014 Oct;16(10):488. doi: 10.1007/s11920-014-0488-2). Psychoeducation was also found effective (see pdf attached).

Here are some good papers : http://www.ncbi.nlm.nih.gov/pubmed/?term=psychotherapy+cancer

well.Oncological disease is not just a single disease, it presents  with host of physiological and psychological conditions which deeper the patients mental troubles,presenting PTSD,social Anxiety,Phobia's etc,so a emphasized psychotherapy is imperative for successful intervention if any to provide some hope and light to these group of patients.

A very good book about this : Pediatric Psycho-oncology: Psychosocial Aspects and Clinical Intervention ,  Shulamith Kreitler et al 2012 , 

Link to get the PDF : http://bookzz.org/md5/0ee97eead9fc117d9dca316bbc94f492

Depending on the target problem (e.g., children anxiety to procedures, distress in the family) there are a number of therapeutic approaches that can be utilized.

I enclose several references that you may find helpful:

Pai et al. A meta-analysis of the effectrs of psychological interventions in pediatric oncology on outcomes of psychological distress and adjustment. J of Ped Psych, 2006, 31, 978-988.

Kaza et al, JPP, 2005, 30, 644-655

Sahler et al, J do Dev and Beh Peds, 2002, 23:77-86, best wishes, m

None if a general assessment, the SCID-P style, doesn't detect clinically significant symptoms? In adult oncology, assessing stress is considered a must in every visit...

Hello Duarte Ribeiro,

below, you can find some recent references to better explore the topic:

guidelines:

Wiener, L., Viola, A., Koretski, J., Perper, E. D., & Patenaude, A. F. (2015). Pediatric psycho-oncology care: standards, guidelines, and consensus reports. Psycho-Oncology, 24(2), 204-211. doi:10.1002/pon.3589

best practice model:

Wiener, L. S., Pao, M., Kazak, A. E., Kupst, M. J., Patenaude, A. F., & Arceci, R. (2015). Pediatric psycho-oncology: A quick reference on the psychosocial dimensions of cancer symptom management (2nd ed.). New York, NY, US: Oxford University Press.

CBT approach:

Last, B. F., & Grootenhuis, M. A. (2012). Psychosocial interventions: A cognitive behavioral approach. In S. Kreitler, M. W. Ben-Arush, A. Martin, S. Kreitler, M. W. Ben-Arush, A. Martin (Eds.) , Pediatric psycho-oncology: Psychosocial aspects and clinical interventions (2nd ed.) (pp. 92-103). Wiley-Blackwell. doi:10.1002/9781119941033.ch9

overall review of the approaches:

Wiener, L., Oppenheim, D., Breyer, J., Battles, H., Zadeh, S., & Patenaude, A. F. (2012). A worldview of the professional experiences and training needs of pediatric psycho-oncologists. Psycho-Oncology, 21(9), 944-953. doi:10.1002/pon.3064

Shemesh, E. (2013). Review of Pediatric psycho-oncology: Psychosocial aspects and clinical interventions. 2nd ed. Journal Of The American Academy Of Child & Adolescent Psychiatry, 52(9), 972-974. doi:10.1016/j.jaac.2013.06.004