I am really sorry to hear about your loss.
You should contact an attorney experienced medical malpractice to have your case reviewed. Your wife's medical records will need to be reviewed by an expert to determine if the tretment was below the standard of care (i.e. if they should have caught the cancer sooner) and if the delay in treatment caused her further damage. Many times in cases like this the outcome would have been the same even if the cancer was caught sooner. It is important to have the case reviewed by an expert so you should call an attorney soon.
I would agree with my colleague and add that you will need to show more likely than not the outcome would have been different, so an expert should be able to review the records and let you know.
The response herein is for informational purposes only is not legal advice and does not create an attorney/client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. I am a lawyer licensed in the State of Maryland only, and I am not your lawyer (unless you have been in my office and signed a contract). This communication is not intended as legal advice, and no attorney client relationship results. Please consult your own attorney for legal advice.
Medical malpractice cases in the great State of Washington are governed by statutes. RCW 7.70. (http://apps.leg.wa.gov/RCW/default.aspx?cite=7.70). The main question is usually whether the health care provider failed to follow the accepted standard of care in the field. RCW 7.70.030. There can also be causes of action for health care providers making promises they didn't fulfil, or acting without the informed consent of the patient.
These cases are extremely difficult and require the testimony of an expert witness. Miller V. Jacoby, 102 Wn. App. 256 (2000). (You can read relevant cases at the MRSC website.) Doctors are trained to work cooperatively (unlike lawyers who are trained to be adversarial), so doctors are often reluctant to testify against each other. Doctors who are willing to testify as expert witness usually charge significant quantities of money to do so, and often must be flown in from out of State.
Some law firms who are really good at medical malpractice cases in Washington State include the following: Chris Otorowski (http://www.medilaw.com/); Chemnick, Moen, Greenstreet (http://cmglaw.com/); and Fuller & Fuller (http://www.fullerlaw.com/).
Only a small percentage of victims of medical malpractice make a claim, and of those that do, only about 20% ever get any money to compensate them. Nonetheless, sometimes justice requires assigning responsibility where it is due.
[In accordance with the Avvo community guidelines, this communication does not constitute "legal advice", nor does it form an attorney-client relationship.]