I think , answer is "sometimes"

1. High serum cancer antigen 125 level indicates perforation in acute appendicitis.

Çetinkaya E, Erdoğan A, Akgül Ö, Çelik C, Tez M.

Am J Emerg Med. 2015 Oct;33(10):1465-7. doi: 10.1016/j.ajem.2015.07.001.

2.Serum total bilirubin elevation is a predictor of the clinicopathological severity of acute appendicitis.

Nomura S, Watanabe M, Komine O, Shioya T, Toyoda T, Bou H, Shibuya T, Suzuki H, Uchida E.

Surg Today. 2014 Jun;44(6):1104-8. doi: 10.1007/s00595-013-0659-5.

3.Diagnostic accuracy of hyperbilirubinaemia in anticipating appendicitis and its severity.

Muller S, Falch C, Axt S, Wilhelm P, Hein D, Königsrainer A, Kirschniak A.

Emerg Med J. 2015 Sep;32(9):698-702. doi: 10.1136/emermed-2013-203349. Epub 2014 Dec 4.

Thanks alot. So the doubt still remains about the preoperative identification.

There are some useful parameters for predicting complicated appendicitis. It is crucial to decide if non-operative treatment could be the choice. A nice manuscript has some of the answers. 

Dig Surg. 2016;33(3):177-81. doi: 10.1159/000444101. Epub 2016 Feb 10.

An Appraisal of Inflammatory Markers in Distinguishing Acute Uncomplicated and Complicated Appendicitis.

Beecher SM1, Hogan J, O''Leary DP, McLaughlin R.

A common severe abdominal pain can often be associated with a dysfunction of the sacroiliac joint.  This is Baer's SI point.  This can occur on either side.  It is on a line from the ASIS to the umbilicus, two inches from the umbilicus.  Not to be confused with the appendicitis point which is two inches from the ASIS.  I saw a patient with a 4 year history of abdominal pain and LBP.  She had both ovaries removed and still had symptoms.  I did a manual posterior innominate correction and she was free of pain in both the low back and abdomen.  She was a little miffed about the unnecessary loss of her ovaries.