Decision #161/99 - Type: Workers Compensation

Preamble

An Appeal Panel hearing was held on June 9, 1999, at the request of an advocate, acting on behalf of the claimant. The Panel discussed this appeal on several occasions, the last one being on November 1, 1999.

Issue

Whether the claim for compensation should be adjudicated using the dominant cause test as provided by Section 4(4) of the Act which became effective January 1, 1992; and

Whether the claim is acceptable.

Decision

That the claim is not acceptable.

Background

On August 15, 1993, the claimant submitted an application for compensation benefits in regard to carcinoma of the tonsil and pharynx. The claimant believed that the cause of these conditions was related to his exposure to grinding dust and welding fumes from working with stainless steel spark arrestors (honeycombs).

The Workers Compensation Board’s (WCB) occupational disease unit gathered information pertinent to the claimant’s occupational/smoking history along with medical information from various specialists. The following is a brief review of preliminary medical documents noted on file.

In a report dated April 23, 1993, an occupational health physician stated that he initially assessed the claimant in March and April 1993, to determine whether cancer of the tonsil and oral pharynx were related to his work as a welder. Taking into consideration the claimant’s occupational and medical histories along with two references related to medical literature, the physician concluded that the claimant’s welding exposures were the dominant cause of his tonsil and pharynx cancer. On July 6, 1993, a medical officer employed with the accident employer disagreed with the occupational health physician indicating there was not enough evidence to make such a conclusion.

On August 23, 1993, a local hospital submitted numerous medical reports regarding the claimant’s medical history. The following is a brief description of each report:

operative report dated April 28, 1992. The pre-operative diagnosis was a left branchial cyst. The post-operative diagnosis was left branchial cyst. The operation performed was “excision cyst left side of neck.”
a pathology report dated April 28, 1992 revealed the following diagnoses in relation to a lesion on the left side of the claimant’s neck:

a) A branchial cleft cyst with squamous carcinoma in-situ in the epithelial lining.
b) A lymph node with metastatic squamous cell carcinoma.
c) Two other lymph nodes with reactive changes.

a CT scan of the neck dated October 5, 1992, revealed “Slight asymmetry in the posterolateral left side of the nasopharynx. No other significant finding is apparent. There is an incidental right maxillary sinus retention cyst.”
on January 14, 1993, the claimant was assessed at a Head & Neck Conference. The report indicated that the claimant’s history went back to late 1991 when he noticed a swelling in the left upper neck. He was seen and assessed by a physician who felt he might have a lymphoma. Investigations including a bone scan and bone marrow were normal. The claimant was then referred to another specialist who felt that the lesion might be a branchial cyst and the lesion was aspirated, following which it completely disappeared. The lesion however, slowly filled up again and in April of that year formal surgical excision of a branchial cyst was done. The pathology report showed a branchial cyst with squamous carcinoma in situ and a lymph node with metastatic squamous cell carcinoma.

It was noted that the claimant had a CT scan which showed some fullness in the vallecula on the left but no frank evidence of tumor and on examination his physical examination was entirely normal. The pathology was reviewed and it was felt the claimant had metastatic squamous cell carcinoma in a lymph node adjacent to a branchial cyst but there was no good evidence that the carcinoma was arising from the branchial cyst. It was the concensus of the conference that the claimant should proceed to an examination under anaesthetic. If no primary site was ascertained at that examination, then close follow-up would be in order. If the patient did have a primary site by inspection or biopsy, then he should proceed to radical radiotherapy as appropriate.

a “History” report dated January 28, 1993, reported the claimant’s smoking history as < 5 pk. yr. hx.
a Discharge Summary report revealed that the claimant was admitted to hospital on January 31, 1993 and underwent a quadroscopy and biopsies. The pre-operative diagnosis was carcinoma of the neck with unknown primary. The post-operative diagnosis was “likely lateral pharyngeal wall and base of tongue squamous CA”.
a pathology report dated February 1, 1993, revealed the following diagnoses:

1. Biopsy of lesion left posterior pharyngeal wall, a fragement of squamous mucosa showing epithelial hyperplasia with edema and lymphoid infiltrates with germinal centre formations in the stroma. The overall appearance is consistent with a polyp. No malignancy is seen.
2. Biopsy of lateral inferior laryngeal wall, a fragment of squamous mucuosa showing no evidence of malignancy.
3. Biopsy base left tonsil, tonsillar tissue, including squamous epithelium, showing no evidence of malignancy
4. Biopsy of left tonsil tissue, tonsillar tissue showing an invasive moderately differentiated squamous cell carcinoma.

hospital reports showed that the claimant had an EUA on February 1, 1993, which showed a carcinoma in the lateral pharyngeal wall on the left. Follow-up reports dated February 11, 1993, March 10, 1993, March 19, 1993, March 24, 1993, March 26, 1993, and April 28, 1993 were included. On July 14, 1993, the treating oncologist stated that the claimant appeared to have recovered well from his radical radiotherapy.

On September 21, 1993, a signed statement was obtained from the claimant which included details regarding his previous work history and information regarding his smoking/alcohol consumption patterns. The claimant also provided information with regard to his exposure to asbestos, cobalt and other chemicals. The claimant felt that his cancer was caused from working with stainless steel welding rods between 1985 to 1990. He was claiming time loss benefits and for any future health problems that may arise.

Following consultation with the WCB’s internal medicine consultant in February 1994, the WCB’s occupational disease unit determined that the claim was not acceptable as it could not establish a relationship between the claimant’s occupation as a welder and diagnosis of carcinoma of the tonsil and pharynx. This decision was reached in accordance with Sections 1(1) and 4(4) of the Workers Compensation Act (the Act). On February 15, 1995, an advocate for the claimant appealed this decision and the case was referred to Review Office.

In a decision dated April 14, 1995, Review Office determined that a Medical Review Panel (MRP) should be convened under section 67(3) of the Act for an opinion on the relationship between the worker’s medical difficulties and his employment. On July 20, 1995, the MRP reported its findings and a copy was distributed to all interested parties.

On August 25, 1995, Review Office determined that the claim was not acceptable. Review Office commented that the worker believed that his employment as a boiler maker and welding stainless steel rods, caused him to develop carcinoma in the left tonsil, lymph nodes, and nasal pharynx area. There was medical support for and against the claimant’s contention of a causal link between the carcinoma and his employment. In order to seek expert medical opinion, Review Office requested a Medical Review Panel consisting of two medical specialists in oncology and the Panel chairperson. According to Review Office, the three physicians in its July 20, 1995, report unanimously determined that the worker’s employment was not the dominant cause of his carcinoma. Based on the weight of medical evidence and section 4(4) of the Act, Review Office determined that the dominant cause of his disease/condition and was not work related.

Subsequent to the above decision, the claimant’s advocate presented a further submission to Review Office dated December 1, 1998, which included a copy of policy 44.20.30.60 entitled Laryngeal Cancer, a summary of the worker’s medical treatment since January 10, 1992, and a medical opinion from a radiation oncologist dated October 8, 1998. In regard to this information, the advocate contended the following:

there was little difference between oral pharyngeal cancer and a laryngeal cancer. The advocate believed that policy 44.20.30.60 should be utilized in the adjudication of the claim because of the claimant’s occupational history.
the advocate felt that the case should be adjudicated under pre-1992 legislation as December 1991 was when the claimant first felt a lump in his left neck and that the dominant cause test should not be utilized in the adjudication of the claim.

On January 22, 1999, Review Office confirmed that the claim for compensation was not acceptable. The members of Review Office agreed that the claim should be adjudicated using the dominant cause test found in section 4(4) as it was amended on January 1, 1992. With regard the advocate’s argument that the worker felt a lump in his neck in 1991, Review Office felt that this factor did not meet the requirements for adjudication of the case utilizing pre-1992 legislation. Section 1(12) of the current compensation act and the pre-1992 act were quoted. Review Office stated, in part, “….which definition of Section 1(12) is used regarding the deemed date of accident, that the worker’s case would fall under the new legislation as he was neither disabled nor did he have an impairment or a loss of wages prior to 1992. This therefore requires the worker’s case to be subject to the dominant cause test.”

Review Office concluded that the MRP did not support the worker’s contention that his employment as a boiler maker was the dominant cause of his diagnosed medical condition. Review Office was of the view that the available evidence did not support the worker’s claim that he had an occupational disease arising out of and in the course of his employment and his claim for compensation was not acceptable.

On June 9, 1999, an Appeal Panel hearing was held at the request of the advocate who appealed the Review Office’s decision. Following the hearing, the Appeal Panel requested additional medical information from two of the claimant’s treating physicians. On September 20, 1999, all parties were provided with copies of the medical documentation obtained by the Appeal Panel and were asked to provide comments. On November 1, 1999, the Panel met to render its final decision.

Reasons

The issues in this appeal are whether the claim for compensation should be adjudicated using the dominant cause test as provided by Section 4(4) of the Act which became effective January 1, 1992, and whether or not the claim is acceptable.

Briefly, the claimant has had the misfortune of being diagnosed over a period of approximately a year with squamous cell carcinoma of three anatomical areas, of the left tonsil, of a left branchial cleft cyst, and of the nasopharynx. These diagnoses, subsequent investigations and treatments resulted from the claimant’s visit to his doctor in December 1991 because of a lump that he found on the left side of his neck. The claimant was referred to specialists who found a squamous cell carcinoma in-situ of a left branchial cyst in 1992 as well as squamous cell carcinoma in an adjacent lymph node. The claimant’s case was reviewed at the Head and Neck Conference at a local tertiary hospital on January 14, 1993 as it was felt that a primary carcinoma arising in a branchial cyst would be quite unusual and that the lymph node involvement was felt to be a metastatic squamous cell carcinoma with no good evidence that the carcinoma arose from the branchial cyst. Further investigations were therefore initiated based on their suspicion that there was a primary carcinoma that had led to this manifestation.

These investigations later confirmed a squamous cell carcinoma in-situ of the nasopharynx and squamous cell carcinoma of the left tonsil with metastases to local lymph nodes. The claimant filed a claim for compensation with the Workers Compensation Board (WCB) in August 1993.

The claimant asserts that his conditions are related to hazards of his occupation as a mechanic and boiler maker/welder, and has provided evidence regarding his job history and exposures to various substances in support of his claim.

The Workers Compensation Act (the Act) only allows for compensation for personal injuries by an accident arising out of and in the course of employment. In order for this claim to be considered, we must first find that there is an “accident,” which is defined in Subsection 1(1) of the Act, as is the term “occupational disease.”

Subsection 1(1) of the Act states, in part:

Definitions

1(1) In this Act

“accident” means a chance event occasioned by a physical or natural cause; and includes

(a) a wilful and intentional act that is not the act of the worker,
(b) any
(i) event arising out of, and in the course of, employment or
(ii) thing that is done and the doing of which arises out of, and in the course of, employment, and
(c) an occupational disease
and as a result of which a worker is injured.
“occupational disease” means a disease arising out of and in the course of employment and resulting from causes and conditions
(a) peculiar to or characteristic of a particular trade or occupation; or
(b) peculiar to the particular employment;
but does not include
(c) an ordinary disease of life; and
(d) stress, other than an acute reaction to a traumatic event.

WCB Policy 44.20 provides some assistance in defining the terminology used in the “occupational disease” portion of the legislation, stating in part:

2. DEFINITIONS RELEVANT TO OCCUPATIONAL DISEASE

A number of terms arise directly from the legislation that require operational definition. For the purpose of this policy the following definitions apply:

a. “peculiar to or characteristic of a particular trade or occupation”
A disease will be described as being peculiar to or characteristic of a particular trade, work process, or occupation if there is a preponderance of scientific evidence to support a conclusion that the nature of the work processes or environment have significantly increased the likelihood of causing a particular disease in the workers who work in that trade or occupation.

b. “peculiar to the particular employment”
A disease will be described as being peculiar to the particular employment if:
1. there are factors identifiable in that workplace that are known to cause the disease, or
2. there is scientific evidence acceptable to the WCB that the particular workplace is the cause of a significantly increased risk of the disease even though the cause has not been identified, or
3. a factor can be identified a the workplace as being the proximate cause of the disease.

We note that there has been considerable medical evidence, animal studies, research abstracts and reports of scientific studies on various types of workers in various work processes and job environments with respect to cancers of different types and anatomical sites submitted with respect to this claim. Documentation of the claimant’s work history and his various job environments also form part of this file. This has given us the opportunity to weigh carefully the issue of whether the claimant’s diagnosed conditions are causally related to the workplace or whether the conditions are an ordinary disease of life.

After a review of all the evidence on file and the representations made at the hearing, we find on a balance of probabilities that the claimant’s diagnosed carcinoma at the three anatomical sites are not peculiar to or characteristic of the claimant’s trade or occupation or to the claimant’s particular employment, and as such we find that there is no “occupational disease” that would lead a finding of an “accident” as required under subsection 1(1) of the Act. On this basis, the claim is not acceptable.

In reaching these conclusions, we note the following evidence:

a medical review panel (MRP) was convened on July 20, 1995, under subsection 67(3) of the Act to consider this claim, with oncology specialists chosen to deal with the questions raised. The MRP’s report notes that they reviewed all medical documentation in the file, interviewed the claimant in respect of his work history and occupational exposures. The panel also reviewed the scientific literature regarding the exposure of welders and other categories of workers to chromium, nickel, and cobalt and their carcinogenic effects and any association to particular types of cancer. The Panellists unanimously confirmed the diagnosis of the claimant’s medical condition as:

1. squamous cell carcinoma of the left tonsil with metastases to the local lymph nodes.
2. squamous cell carcinoma in-situ in a branchial cyst.
3. carcinoma in-situ in the nasopharynx.

We note in particular the response of the panel in Question 2 regarding scientific evidence as to a causal relationship of those conditions to the workplace:

“Question #2: Taking into account the nature of this worker’s employment, was his employment as a boilermaker the dominant cause of his diagnosed condition? Please explain your conclusions.
Answer: The agree unanimously that it is not possible to state that this worker’s employment as a boilermaker was a dominant cause of the above diagnosed conditions.
The agree that there is no clear evidence from the literature that cancer in the nasopharyngeal area is linked to exposure to chromium, nickel, or cobalt.” [emphasis ours]

We also note as part of the MRP deliberations two reports from the oncologists both dated July 24, 1995 relating to their findings in particular with respect to cobalt exposure. One oncologist reported the following:

“ There is no strong or definitive evidence for causal relationship between chromium, nickel and cobalt exposure and squamous cell carcinoma of the head and neck in terms of clinical or epidemiological studies. The information on cobalt that we reviewed that was not available during the panel discussion shows even less evidence for any human carcinogenic risk for cobalt via a variety of different routes. Certainly there is no clear evidence relating it to squamous cell carcinoma of the head and neck.
In this unfortunate case, I am unable to link Mr. [the claimant’s] cancer, occupation as a welder and his pharyngeal cancer with evidence from the scientific literature.”

The second oncologist reported the following:

“ From the abstracts that were printed I am not able to identify any which refer to the fact that cobalt is associated with an increased risk of pharyngeal carcinoma. The abstracts suggest that cobalt is weakly carcinogenic and that there is inadequate evidence that cobalt causes carcinogenicity in humans. Animal studies that have looked at inhaled cobalt have failed to demonstrate an increase in the number of cancers. On the basis of this information I do not believe that cobalt could be implicated as a significant contributor to Mr. [the claimant’s] carcinoma.”

The claimant’s advocate has argued that the WCB does have a special policy 44.20.30.60 which recognizes the link between laryngeal cancer and occupational exposure to asbestos and nickel, once certain exposure and latency periods are met. The advocate has suggested that since the claimant was exposed to both at various points of his employment and since the nasopharyngeal and laryngeal areas are anatomically close, that the WCB should consider the carcinomas of the pharyngeal areas under its laryngeal cancer policy. In support of this argument, the advocate relies on an opinion of an oncologist dated October 8, 1998 who states that the cancer cell types are the same for both anatomical areas, and that:

“I find the distinction between oropharygeal cancer and laryngeal cancer somewhat artificial and I think that if the gentleman had had a laryngeal cancer and would qualify, then I think that it would seem to be highly reasonable that he should also qualify with an oropharyngeal cancer.”

With due respect, we note the oncologist does not confirm that the claimant would qualify under the policy if his diagnosis was that of laryngeal cancer. We place little weight on this argument and the supporting report for the following reasons:

a. when asked by the advocate if there are any more current studies or any connection between oropharyngeal cancer and exposure to asbestos, nickel chromium and/or cobalt, the specialist answers,
“A literature search has been conducted using Medline with neck and neck neoplasms from 1994 onwards. No additional studies have specifically addressed this.”
b. when asked by the advocate if the claimant’s exposures were sufficient, the oncologist stated he could not comment on the content of the claimant’s work history, on the risks associated with various welding techniques, or as to the duration of exposures.

We find that this restricts the oncologist’s comments to a general discussion of potential linkages between occupational exposures and the development of certain cancers, and is therefore of little value in establishing that there were factors peculiar to the claimant’s particular employment that may have caused the cancer conditions.

WCB Policy on Laryngeal Cancer is a policy which deals specifically with laryngeal cancer and therefore is a defined “exception” to the general policy regarding the tests to be used in defining an occupational disease. It is part of a limited group of medical conditions where scientific evidence has been accepted by the WCB Board of Directors as having established a causal link between a medical condition and occupational exposures where certain criteria for exposure and latency periods have been met.

None of the claimant’s diagnoses involve the larynx and therefore we find that the policy with respect to laryngeal cancer is not applicable in this case. We note that carcinoma of the branchial cleft, tonsil and nasopharynx are not the subject of any specific WCB policy and therefore the general disease policy would apply.

In fact, the oncologist consulted by the advocate acknowledges that oropharyngeal cancer occurs less frequently than laryngeal cancer and that this is likely the result of airflow or differing sensitivities of the tissues in each area. The oncologist also indicates that carcinoma of the tonsil is the most common variety of cancer of the head and neck. The above observations, in our opinion, suggest that the etiology of the claimant’s diagnoses and laryngeal cancer can be distinct.

As such, we have no basis under which to extend the coverage of the narrowly defined laryngeal cancer policy to carcinoma occurring in other anatomical sites. Rather, we are required to consider the claimant’s conditions in the context of the legislation and policy 44.20 which deals generally with occupational disease, giving due regard and weight to the scientific evidence, occupational exposures, latency periods, or other factors, as circumstances of the case may require.

As previously noted, the oncologist acknowledges that the claimant’s diagnosed carcinoma of the tonsil is the most common variety of cancer of the head and neck and we note this is confirmed also in the research literature submitted. We also note that there is evidence on file which apparently suggests that the carcinoma of the tonsil was the primary site of the claimant’s cancer and in that regard we note that metastases to the local lymph nodes from this site had taken place and that the other two sites of the left branchial cyst and the nasopharynx had reportedly revealed squamous cell carcinoma in-situ. In this regard we note in a report to the Appeal Commission dated July 26, 1999 the attending physician indicates:

“ Basically this man presented to me originally with a large cyst in the left neck that appeared for all the world to be a branchial cleft cyst. Following excision and several pathological examinations it became evident that there was epidermoid carcinoma in the wall of the cyst. These have been reported to occur in branchial cleft cysts but most often squamous cell cancer in the neck has an upper aerodigestive epithelial origin. After some searching it was found that he had a very small epithelial cancer in the left tonsil. Because of the small size and the previous neck surgery it was recommended that he have the radiation therapy to cure the primary lesion and treat the nodes in the neck. ” (emphasis ours)

This makes it difficult for us to attach any significant enhanced risk from occupational exposure to this type of cancer at the three identified sites, as compared to the risks faced by the general population in contracting this condition as an ordinary disease of life.

After consideration of all the evidence, we place the greatest weight on and accept the findings of the Medical Review Panel that there is no clear evidence of a linkage between any of the diagnosed cancers of the left tonsil, the left branchial cyst and the nasopharyngeal areas suffered by the claimant and his occupational exposures in the workplace. As such, we find that there is no “occupational disease” as defined in subsection 1(1) of the Act, and thus we find that there is no “accident” as required under the same subsection. On this basis, we find that the claim is not acceptable, and deny the claimant’s appeal.

The claimant’s advocate has argued that the appropriate test with respect to the adjudication of this claim would be pursuant to the provisions of the Act prior to January 1, 1992 and has presented arguments in support of a deemed date of accident in 1991 from which different adjudicative tests for compensation of an occupational/industrial disease would flow.

With due respect to the arguments brought forward by the claimant’s advocate, we find that this issue is moot, given our findings in respect of claim acceptability.

Both the old Act (subsection 1(12)) and new Act (subsection 1(12)) have a provision that allow a date of accident to be deemed where an accident is caused by an industrial or occupational disease. The deeming of a date of accident presupposes that a causal link – an occupational/industrial disease as defined in subsection 1(1) of the Act -- has already been established. In other words, where the criteria of an “accident” as defined by subsection 1(1) must first be met. As noted above, we have been unable to make such a finding, and thus the determination of a deemed date of accident is not at issue.

Similarly, the issue of whether to use the proportionality rules under subsection 4(4) of the old Act or the dominant cause test under subsection 4(4) of the new Act both have wording referring to industrial or occupational disease. Again, these sections presuppose a finding under subsection 1(1) of the Act, that there was an accident caused by an industrial or occupational disease. As we have been unable to make such a finding, there is no “occupational disease” available to be assessed against non-work factors under either test. We find that the issue as to which test applies is therefore moot, and cannot be adjudicated without the finding of a qualifying “accident” under the Act.

Panel Members

D.A. Vivian, Presiding Officer
A. Finkel, Commissioner
R. Frisken, Commissioner

Recording Secretary, B. Miller

D.A. Vivian - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 23rd day of November, 1999

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